Change search
Refine search result
1234 51 - 100 of 167
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Rows per page
  • 5
  • 10
  • 20
  • 50
  • 100
  • 250
Sort
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
Select
The maximal number of hits you can export is 250. When you want to export more records please use the Create feeds function.
  • 51. Kaida, Kosuke
    et al.
    Åkerstedt, Torbjörn
    Stockholm University, Faculty of Social Sciences, Stress Research Institute.
    Takahashi, Masaya
    Vestergren, Peter
    Gillberg, Mats
    Lowden, Arne
    Stockholm University, Faculty of Social Sciences, Stress Research Institute.
    Kecklund, Göran
    Stockholm University, Faculty of Social Sciences, Stress Research Institute.
    Portin, Christian
    Stockholm University, Faculty of Social Sciences, Stress Research Institute.
    Performance prediction by sleepiness-related subjective symptoms during 26-hour sleep deprivation2008In: Sleep and Biological Rhythms, ISSN 1446-9235, E-ISSN 1479-8425, Vol. 6, p. 234-241Article in journal (Refereed)
    Abstract [en]

    Sleepiness is a major cause of lower productivity and higher risk of accidents in various work situation. Developing sleepiness monitoring techniques is important to important to improve work efficiency and to reduce accident risk, so that people can take a rest/break in appropriate timing before an accident or a mistake occurs. The aim of the present study are (1) to explain subjective sleepiness using sleep-related symptoms, and (2) to examine which symptoms are useful to predict performance errors. Participants were healthy paid volunteers (six males, six females; mean ± SD, 31.5 ± 10.74 years). Participants took part in 26-h sleep deprivation. During sleep deprivation, they carried out several performance tasks every 3 h and an hourly rating of questionnaires to evaluate subjective symptoms including two types of Karolinska Sleepiness Scale (KSS). The present study confirmed that performance errors can be predicted by subjective symptoms. While mental fatigue was correlated to KSS scores linearly, eye-related subjective symptoms showed quadratic correlation to KSS. By taking into consideration this noteworthy relationskap between subjective symptoms and sleepiness, more accurate introspection of sleepiness and performance errors prediction (detection) may be possible.

  • 52.
    Kecklund, Göran
    et al.
    Stockholm University, Faculty of Social Sciences, Stress Research Institute.
    Ingre, Michael
    Stockholm University, Faculty of Social Sciences, Stress Research Institute.
    Åkerstedt, Torbjörn
    Stockholm University, Faculty of Social Sciences, Stress Research Institute.
    What characterizes good and bad shift schedules?2013Conference paper (Refereed)
  • 53.
    Kecklund, Göran
    et al.
    Stockholm University, Faculty of Social Sciences, Stress Research Institute.
    Milia, Lee Di
    Axelsson, John
    Lowden, Arne
    Stockholm University, Faculty of Social Sciences, Stress Research Institute.
    Åkerstedt, Torbjörn
    Stockholm University, Faculty of Social Sciences, Stress Research Institute.
    20th International Symposium on Shiftwork and Working Time: Biological Mechanisms, Recovery, and Risk Management in the 24-h Society2012In: Chronobiology International, ISSN 0742-0528, E-ISSN 1525-6073, Vol. 29, no 5, p. 531-536Article in journal (Refereed)
    Abstract [en]

    This dedicated issue of Chronobiology International is devoted to the selected proceedings of the 20th International Symposium on Shift Work and Working Time held in Stockholm, Sweden, 28 June to 1 July 2011. It constitutes the fifth such issue of the journal since 2004 dedicated to the selected proceedings to the meetings of the Working Time Society. The key theme of the 20th Symposium was "Biological Mechanisms, Recovery, and Risk Management in the 24-h Society." The collection of papers of this dedicated issue represents the best of contemporary research on the effects of night and rotating shift schedules on worker health and safety. The contents cover such topics as sleep restriction, injuries, health, and performance of night work and rotating shiftwork, plus light treatment as a countermeasure against the circadian disruption of shiftwork. The majority of the papers are observational field studies, including some of large sample size, and three studies are well-designed laboratory experiments. (Author correspondence: goran.kecklund@stress.su.se ).

  • 54.
    Kecklund, Göran
    et al.
    Stockholm University, Faculty of Social Sciences, Stress Research Institute.
    Söderström, Marie
    Åkerstedt, Torbjörn
    Stockholm University, Faculty of Social Sciences, Stress Research Institute.
    Att motverka sömnstörning: orsaker och behandling2008In: Preventiv medicin: Teori och praktik, Studentlitteratur, Lund , 2008, p. 115-126Chapter in book (Other academic)
  • 55. Knutsson, Anders
    et al.
    Alfredsson, Lars
    Karlsson, Berndt
    Åkerstedt, Torbjörn
    Stockholm University, Faculty of Social Sciences, Stress Research Institute.
    Fransson, Eleonor I.
    Westerholm, Peter
    Westerlund, Hugo
    Stockholm University, Faculty of Social Sciences, Stress Research Institute.
    Breast cancer among shift workers: results of the WOLF longitudinal cohort study2013In: Scandinavian Journal of Work, Environment and Health, ISSN 0355-3140, E-ISSN 1795-990X, Vol. 39, no 2, p. 170-177Article in journal (Refereed)
    Abstract [en]

    OBJECTIVE: The aim of this study was to investigate whether shift work (with or without night work) is associated with increased risk of breast cancer. METHODS: The population consisted of 4036 women. Data were obtained from WOLF (Work, Lipids, and Fibrinogen), a longitudinal cohort study. Information about baseline characteristics was based on questionnaire responses and medical examination. Cancer incidence from baseline to follow-up was obtained from the national cancer registry. Two exposure groups were identified: shift work with and without night work. The group with day work only was used as the reference group in the analysis. Cox regression analysis was used to calculate relative risk. RESULTS: In total, 94 women developed breast cancer during follow-up. The average follow-up time was 12.4 years. The hazard ratio for breast cancer was 1.23 [95% confidence interval (95% CI) 0.70-2.17] for shifts without night work and 2.02 (95% CI 1.03-3.95) for shifts with night work. When including only women <60 years of age, the risk estimates were 1.18 (95% CI 0.67-2.07) for shifts without night work, and 2.15 (95% CI 1.10-4.21) for shifts with night work. CONCLUSIONS: Our results indicate an increased risk for breast cancer among women who work shifts that includes night work.

  • 56.
    Lasselin, Julie
    et al.
    Stockholm University, Faculty of Social Sciences, Stress Research Institute. Karolinska Institutet, Sweden.
    Rehman, Javaid-Ur
    Åkerstedt, Torbjörn
    Stockholm University, Faculty of Social Sciences, Stress Research Institute. Karolinska Institutet, Sweden.
    Lekander, Mats
    Stockholm University, Faculty of Social Sciences, Stress Research Institute. Karolinska Institutet, Sweden.
    Axelsson, John
    Stockholm University, Faculty of Social Sciences, Stress Research Institute. Karolinska Institutet, Sweden.
    Effect of long-term sleep restriction and subsequent recovery sleep on the diurnal rhythms of white blood cell subpopulations.2015In: Brain, behavior, and immunity, ISSN 0889-1591, E-ISSN 1090-2139, Vol. 47, no SI, p. 93-99Article in journal (Refereed)
    Abstract [en]

    While acute modifications of sleep duration induces a wide array of immune function alterations, less is known of how longer periods with insufficient sleep affect immune functions and how they return to normal once recovery sleep is obtained. The purpose of the present study was to investigate the effects of five days of restricted sleep and a subsequent 7-day period of sleep recovery on white blood cell (WBC) subpopulation count and diurnal rhythms. Nine healthy males participated in a sleep protocol consisting of two baseline days (8h of sleep/night), five nights with restricted sleep (4h of sleep/night) and seven days of recovery sleep (8h of sleep/night). During nine of these days, blood was drawn hourly during night-time end every third hour during daytime, and differential WBC count was analyzed. Gradual increase across the days of sleep restriction was observed for total WBC (p<.001), monocytes (p<.001), neutrophils (p<.001) and lymphocytes (p<.05). Subsequent recovery sleep resulted in a gradual decrease in monocytes (p<.001) and lymphocytes (p=.001), but not in neutrophils that remained elevated over baseline level at the end of the 7-day recovery period. These effects were associated with altered diurnal rhythms of total WBC and neutrophils, restricted sleep being associated with higher levels during the night and at awakening, resulting in a flattening of the rhythm. The diurnal alterations were reversed when recovery sleep was allowed, although the amplitude of total WBC, neutrophils and monocytes was increased at the end of the recovery period in comparison to baseline. Altogether, these data show that long-term sleep restriction leads to a gradual increase of circulating WBC subpopulations and alterations of the respective diurnal rhythms. Although some of the effects caused by five days of restricted sleep were restored within the first days of recovery, some parameters were not back to baseline even after a period of seven recovery days.

  • 57.
    Leineweber, Constanze
    et al.
    Stockholm University, Faculty of Social Sciences, Stress Research Institute.
    Kecklund, Göran
    Stockholm University, Faculty of Social Sciences, Stress Research Institute.
    Theorell, Töres
    Stockholm University, Faculty of Social Sciences, Stress Research Institute. Karolinska institutet, Sverige.
    Åkerstedt, Torbjörn
    Stockholm University, Faculty of Social Sciences, Stress Research Institute.
    Alexanderson, Kristina
    Westerlund, Hugo
    Stockholm University, Faculty of Social Sciences, Stress Research Institute.
    Inflytande över arbetstiden och sjuknärvaro/sjukfrånvaro2013In: Arbetsmarknad & Arbetsliv, ISSN 1400-9692, Vol. 19, no 4, p. 87-99Article in journal (Other academic)
    Abstract [sv]

    Flexibla arbetstider blir allt vanligare. De förväntas underlätta verksamhetens förmåga att hantera arbetstoppar, tillgodose anställdas behov av livsbalans samt möjliggöra bättre hälsa och arbetsprestation. Flexibilitet skapas ofta genom att de anställda ges inflytande över arbetstiderna. Vetenskaplig kunskap om sambandet mellan arbetstidskontroll och sjukfrånvaro/sjuknärvaro saknas nästan helt. I föreliggande studie undersöks sambandet mellan arbetstidskontroll samt dess underdimensioner och självrapporterad sjukfrånvaro/sjuknärvaro i ett representativt urval av den arbetande befolkningen i Sverige.

  • 58.
    Lekander, Mats
    et al.
    Stockholm University, Faculty of Social Sciences, Stress Research Institute. Karolinska Institutet, Sweden.
    Andreasson, Anna Nixon
    Stockholm University, Faculty of Social Sciences, Stress Research Institute. Karolinska Institutet, Sweden.
    Kecklund, Göran
    Stockholm University, Faculty of Social Sciences, Stress Research Institute.
    Ekman, Rolf
    Ingre, Michael
    Stockholm University, Faculty of Social Sciences, Stress Research Institute.
    Åkerstedt, Torbjorn
    Stockholm University, Faculty of Social Sciences, Stress Research Institute.
    Axelsson, John
    Subjective health perception in healthy young men changes in response to experimentally restricted sleep and subsequent recovery sleep2013In: Brain, behavior, and immunity, ISSN 0889-1591, E-ISSN 1090-2139, Vol. 34, p. 43-46Article in journal (Refereed)
    Abstract [en]

    Sleep and subjective health are both prospectively related to objective indices of health and health care use. Here, we tested whether five days with restricted sleep and subsequent recovery days affect subjective health and is related to increased levels of circulating IL-6 and TNF-α and fatigue. Nine healthy men (23-28years) went through a 6-week sleep protocol with subjects as their own controls in a repeated measures design with a total of 11 nights in a sleep laboratory. The experimental part of the protocol included three baseline days (sleep 23-07h), five days with sleep restriction (03-07h) and three recovery days (23-07h) in the sleep laboratory. Subjective health and fatigue was recorded daily. Eight blood samples were drawn each day (every third hour) on 8days of the protocol and analyzed with respect to IL-6 and TNF-α. Subjective health deteriorated gradually during restricted sleep (p=.002) and returned to baseline levels after three days of recovery. IL-6 and TNF-α did not change significantly. Fatigue increased gradually during sleep restriction (p=.001), which significantly contributed to the association between restricted sleep and subjective health. The study is the first to show that subjective health is directly responsive to changes in sleep length and related to increased fatigue. Thus, subjective health is differently appraised after manipulation of one of its presumed determinants. Larger experimental studies would be beneficial to further distinguish causation from association regarding the underpinnings of subjective health.

  • 59.
    Lindblad, Frank
    et al.
    Stockholm University, Faculty of Social Sciences, Stress Research Institute.
    Backman, Lena
    Lundin, A
    Åkerstedt, Torbjörn
    Stockholm University, Faculty of Social Sciences, Stress Research Institute.
    Sleep, stress and eating attitudes predict concentration at school2011In: Salud (i) Ciencia, ISSN 1667-8982, E-ISSN 1667-8990, Vol. 18, no 2, p. 142-146Article in journal (Refereed)
    Abstract [en]

    Background: Sleep, stress and eating habits may affect concentration in school. These factors are probably interrelated, but have never been studied together as predictors of concentration. The purpose of this study, based on secondary analysis of previously collected data, was to evaluate if/how low sleep quality, perceived stress and negative attitudes to eating at school predict self-reported concentration difficulties in school in 11-15-year-olds. Methods: 1 124 students (grades 6-9) from 14 schools (a representative sample from a metropolitan area) filled in a questionnaire at school with questions about socio-demographic data, sleep, perceived stress, school eating attitudes and concentration in school. Results: Logistic regression analysis with mutual adjustment for all predictors, as well as for grade and gender yielded an odds ratio (OR) for the stress component "pressure" of 3.05 (95% confidence interval [CI] = 2.73-4.38), OR = 1.70 (1.20-2.42) for school eating attitude, and OR = 2.57 (1.78-3.71) for difficulties sleeping. Conclusion: Sleep, stress, and eating attitudes independently seem to predict perceived problems of concentration in school, suggesting that a multi-focus approach of life-style patterns may be suitable when trying to improve students' ability to concentrate in school.

  • 60. Lindsäter, Elin
    et al.
    Axelsson, Erland
    Salomonsson, Sigrid
    Santoft, Fredrik
    Ejeby, Kersti
    Ljótsson, Brjann
    Åkerstedt, Torbjorn
    Stockholm University, Faculty of Social Sciences, Stress Research Institute.
    Lekander, Mats
    Stockholm University, Faculty of Social Sciences, Stress Research Institute. Karolinska Institutet, Sweden.
    Hedman-Lagerlöf, Erik
    Internet-Based Cognitive Behavioral Therapy for Chronic Stress: A Randomized Controlled Trial2018In: Psychotherapy and Psychosomatics, ISSN 0033-3190, E-ISSN 1423-0348, Vol. 87, no 5, p. 296-305Article in journal (Refereed)
    Abstract [en]

    Background: Prolonged exposure to stress can lead to substantial suffering, impairment and societal costs. However, access to psychological treatment is limited. Internet-based cognitive behavioral therapy (ICBT) can be effective in reducing symptoms of stress, but little is known of its effects in clinical samples. The aim of this study was to investigate the efficacy of ICBT for patients suffering from chronic stress, operationalized as adjustment disorder (AD) and exhaustion disorder (ED). Methods: A total of 100 adults diagnosed with AD or ED were randomly assigned to a 12-week ICBT (n = 50) or waitlist control condition (n = 50). Primary outcome was the level of perceived stress (PSS). Secondary outcomes included several mental health symptom domains as well as functional impairment and work ability. All outcomes were assessed at baseline, after treatment and at the 6-month follow-up. The study was preregistered at Clinicaltrials.gov: NCT02540317. Results: Compared to the control condition, patients in the ICBT group made large and significant improvements on the PSS (d = 1.09) and moderate to large improvements in secondary symptom domains. Effects were maintained at the 6-month follow-up. There was no significant between-group effect on functional impairment or work ability. Conclusions: A relatively short ICBT is indicated to be effective in reducing stress-related symptoms in a clinical sample of patients with AD and ED, and has the potential to substantially increase treatment accessibility. Results must be replicated, and further research is needed to understand the relationship between symptom reduction, functional impairment and work ability.

  • 61.
    Lowden, Arne
    et al.
    Stockholm University, Faculty of Social Sciences, Stress Research Institute.
    Kecklund, Göran
    Stockholm University, Faculty of Social Sciences, Stress Research Institute.
    Åkerstedt, Torbjorn
    Stockholm University, Faculty of Social Sciences, Stress Research Institute.
    Magnusson Hanson, Linda
    Stockholm University, Faculty of Social Sciences, Stress Research Institute.
    Westerlund, Hugo
    Stockholm University, Faculty of Social Sciences, Stress Research Institute.
    Daylight exposure in the in-door working population in Sweden, relation to sleep, wakefulness and health2013Conference paper (Refereed)
  • 62.
    Lowden, Arne
    et al.
    Stockholm University, Faculty of Social Sciences, Stress Research Institute.
    Nagai, Roberta
    Stockholm University, Faculty of Social Sciences, Stress Research Institute.
    Åkerstedt, Torbjörn
    Karolinska Institutet, Sweden.
    Mild, Kjell Hansson
    Hillert, Lena
    Effects of evening exposure to electromagnetic fields emitted by 3G mobile phones on health and night sleep EEG architecture2019In: Journal of Sleep Research, ISSN 0962-1105, E-ISSN 1365-2869, Vol. 28, no 4, article id UNSP e12813Article in journal (Refereed)
    Abstract [en]

    Studies on sleep after exposure to radiofrequency electromagnetic fields have shown mixed results. We investigated the effects of double-blind radiofrequency exposure to 1,930-1,990 MHz, UMTS 3G signalling standard, time-averaged 10 g specific absorption rate of 1.6 W kg(-1) on self-evaluated sleepiness and objective electroencephalogram architecture during sleep. Eighteen subjects aged 18-19 years underwent 3.0 hr of controlled exposure on two consecutive days 19:45-23:00 hours (including 15-min break); active or sham prior to sleep, followed by full-night 7.5 hr polysomnographic recordings in a sleep laboratory. In a cross-over design, the procedure was repeated a week later with the second condition. The results for sleep electroencephalogram architecture showed no change after radiofrequency exposure in sleep stages compared with sham, but power spectrum analyses showed a reduction of activity within the slow spindle range (11.0-12.75 Hz). No differences were found for self-evaluated health symptoms, performance on the Stroop colour word test during exposure or for sleep quality. These results confirm previous findings that radiofrequency post-exposure in the evening has very little influence on electroencephalogram architecture but possible on spindle range activity.

  • 63.
    Lowden, Arne
    et al.
    Stockholm University, Faculty of Social Sciences, Stress Research Institute. Karolinska Institute, Sweden.
    Åkerstedt, Torbjörn
    Stockholm University, Faculty of Social Sciences, Stress Research Institute. Karolinska Institute, Sweden.
    Assessment of a new dynamic light regimen in a nuclear power control room without windows on quickly rotating shiftworkers-effects on health, wakefulness, and circadian alignment: a pilot study2012In: Chronobiology International, ISSN 0742-0528, E-ISSN 1525-6073, Vol. 29, no 5, p. 641-649Article in journal (Refereed)
    Abstract [en]

    The aim of the study was to test whether a new dynamic light regime would improve alertness, sleep, and adaptation to rotating shiftwork. The illumination level in a control room without windows at a nuclear power station was ∼200 lux (straight-forward horizontal gaze) using a weak yellow light of 200 lux, 3000 K (Philips Master TLD 36 W 830). New lighting equipment was installed in one area of the control room above the positions of the reactor operators. The new lights were shielded from the control group by a distance of >6 m, and the other operators worked at desks turned away from the new light. The new lights were designed to give three different light exposures: (i) white/blue strong light of 745 lux, 6000 K; (ii) weak yellow light of 650 lux, 4000 K; and (iii) yellow moderate light of 700 lux, 4000 K. In a crossover design, the normal and new light exposures were given during a sequence of three night shifts, two free days, two morning shifts, and one afternoon shift (NNN + MMA), with 7 wks between sessions. The operators consisted of two groups; seven reactor operators from seven work teams were at one time exposed to the new equipment and 16 other operators were used as controls. The study was conducted during winter with reduced opportunities of daylight exposure during work, after night work, or before morning work. Operators wore actigraphs, filled in a sleep/wake diary, including ratings of sleepiness on the Karolinska Sleepiness Scale (KSS) every 2 h, and provided saliva samples for analysis of melatonin at work (every 2nd h during one night shift and first 3 h during one morning shift). Results from the wake/sleep diary showed the new light treatment increased alertness during the 2nd night shift (interaction group × light × time, p < .01). Time of waking was delayed in the light condition after the 3rd night shift (group × light, p < .05), but the amount of wake time during the sleep span increased after the 2nd night shift (p < .05), also showing a tendency to affect sleep efficiency (p < .10). Effects on circadian phase were difficult to establish given the small sample size and infrequent sampling of saliva melatonin. Nonetheless, it seems that appropriate dynamic light in rooms without windows during the dark Nordic season may promote alertness, sleep, and better adaptation to quickly rotating shiftwork. (Author correspondence: arne.lowden@stress.su.se ).

  • 64.
    Lowden, Arne
    et al.
    Stockholm University, Faculty of Social Sciences, Stress Research Institute.
    Åkerstedt, Torbjörn
    Stockholm University, Faculty of Social Sciences, Stress Research Institute.
    Ingre, Michael
    Stockholm University, Faculty of Social Sciences, Stress Research Institute.
    Wiholm, Clairy
    Hillert, Lena
    Kuster, Niels
    Nilsson, Jens P.
    Arnetz, Bengt
    Sleep after mobile phone exposure in subjects with mobile phone-related symptoms2011In: Bioelectromagnetics, ISSN 0197-8462, E-ISSN 1521-186X, Vol. 32, no 1, p. 4-14Article in journal (Refereed)
    Abstract [en]

    Several studies show increases in activity for certain frequency bands (10-14 Hz) and visually scored parameters during sleep after exposure to radiofrequency electromagnetic fields. A shortened REM latency has also been reported. We investigated the effects of a double-blind radiofrequency exposure (884 MHz, GSM signaling standard including non-DTX and DTX mode, time-averaged 10 g psSAR of 1.4 W/kg) on self-evaluated sleepiness and objective EEG measures during sleep. Forty-eight subjects (mean age 28 years) underwent 3 h of controlled exposure (7:30-10:30 PM; active or sham) prior to sleep, followed by a full-night polysomnographic recording in a sleep laboratory. The results demonstrated that following exposure, time in Stages 3 and 4 sleep (SWS, slow-wave sleep) decreased by 9.5 min (12%) out of a total of 78.6 min, and time in Stage 2 sleep increased by 8.3 min (4%) out of a total of 196.3 min compared to sham. The latency to Stage 3 sleep was also prolonged by 4.8 min after exposure. Power density analysis indicated an enhanced activation in the frequency ranges 0.5-1.5 and 5.75-10.5 Hz during the first 30 min of Stage 2 sleep, with 7.5-11.75 Hz being elevated within the first hour of Stage 2 sleep, and bands 4.75-8.25 Hz elevated during the second hour of Stage 2 sleep. No pronounced power changes were observed in SWS or for the third hour of scored Stage 2 sleep. No differences were found between controls and subjects with prior complaints of mobile phone-related symptoms. The results confirm previous findings that RF exposure increased the EEG alpha range in the sleep EEG, and indicated moderate impairment of SWS. Furthermore, reported differences in sensitivity to mobile phone use were not reflected in sleep parameters.

  • 65.
    Magnusson Hanson, Linda
    et al.
    Stockholm University, Faculty of Social Sciences, Stress Research Institute.
    Chungkham, Holendro Singh
    Stockholm University, Faculty of Social Sciences, Stress Research Institute.
    Åkerstedt, Torbjörn
    Stockholm University, Faculty of Social Sciences, Stress Research Institute.
    Westerlund, Hugo
    Stockholm University, Faculty of Social Sciences, Stress Research Institute.
    The Role of Sleep Disturbances in the Longitudinal Relationship Between Psychosocial Working Conditions, Measured by Work Demands and Support, and Depression.2014In: Sleep, ISSN 0161-8105, E-ISSN 1550-9109, Vol. 37, no 12, p. 1977-1985Article in journal (Refereed)
    Abstract [en]

    Study Objectives: Because work demands and lack of social support seem to be prospectively linked to sleep problems, and sleep problems are linked to depression, sleep problems may play a role in the relationship between these work characteristics and depressive symptoms. In order to shed more light on this relationship, the current study investigated whether disturbed sleep is a mediator in the longitudinal relationships between work demands, social support, and depression.

    Design: Longitudinal cohort study with repeated survey measures on four occasions.

    Setting: Swedish workforce.

    Participants: 2,017 working participants from the Swedish Longitudinal Occupational Survey of Health in 2006, 2008, 2010, and 2012.

    Measurements and results: Work demands (four items) and social support (six items) were assessed with the Demand Control Questionnaire, disturbed sleep (four items) with the Karolinska Sleep Questionnaire, and depressive symptoms with a brief subscale (six items) from the Symptom Checklist. Autoregressive longitudinal mediation models using structural equation modeling were tested. The work characteristics, and disturbed sleep, were found to be separately associated with depressive symptoms in subsequent waves. However, only demands were found to be longitudinally related to subsequent disturbed sleep. The longitudinal autoregressive models supported a weak mediating role of disturbed sleep in the relationship between demands and depressive symptoms (standardized beta 0.008, P < 0.001), but not between support and depressive symptoms.

    Conclusions: These results indicate that higher demands at work might cause an increase in depressive symptoms, in part, by increasing disturbed sleep, although the mediated effect was relatively small compared to the total effect.

  • 66.
    Magnusson Hanson, Linda L.
    et al.
    Stockholm University, Faculty of Social Sciences, Stress Research Institute.
    Åkerstedt, Torbjörn
    Stockholm University, Faculty of Social Sciences, Stress Research Institute.
    Näswall, Katharina
    Stockholm University, Faculty of Social Sciences, Department of Psychology.
    Leineweber, Constanze
    Stockholm University, Faculty of Social Sciences, Stress Research Institute.
    Theorell, Töres
    Stockholm University, Faculty of Social Sciences, Stress Research Institute.
    Westerlund, Hugo
    Stockholm University, Faculty of Social Sciences, Stress Research Institute. Stockholm University, Faculty of Social Sciences, Department of Psychology.
    Cross-lagged relationships between workplace demands, control, support, and sleep problems2011In: Sleep, ISSN 0161-8105, E-ISSN 1550-9109, Vol. 34, no 10, p. 1403-1410Article in journal (Refereed)
    Abstract [en]

    STUDY OBJECTIVES: Sleep problems are experienced by a large part of the population. Work characteristics are potential determinants, but limited longitudinal evidence is available to date, and reverse causation is a plausible alternative. This study examines longitudinal, bidirectional relationships between work characteristics and sleep problems.

    DESIGN: Prospective cohort/two-wave panel.

    SETTING: Sweden.

    PARTICIPANTS: 3065 working men and women approximately representative of the Swedish workforce who responded to the 2006 and 2008 waves of the Swedish Longitudinal Occupational Survey of Health (SLOSH).

    INTERVENTIONS: N/A.

    MEASUREMENTS AND RESULTS: Bidirectional relationships between, on the one hand, workplace demands, decision authority, and support, and, on the other hand, sleep disturbances (reflecting lack of sleep continuity) and awakening problems (reflecting feelings of being insufficiently restored), were investigated by structural equation modeling. All factors were modeled as latent variables and adjusted for gender, age, marital status, education, alcohol consumption, and job change. Concerning sleep disturbances, the best fitting models were the "forward" causal model for demands and the "reverse" causal model for support. Regarding awakening problems, reciprocal models fitted the data best.

    CONCLUSIONS: Cross-lagged analyses indicates a weak relationship between demands at Time 1 and sleep disturbances at Time 2, a "reverse" relationship from support T1 to sleep disturbances T2, and bidirectional associations between work characteristics and awakening problems. In contrast to an earlier study on demands, control, sleep quality, and fatigue, this study suggests reverse and reciprocal in addition to the commonly hypothesized causal relationships between work characteristics and sleep problems based on a 2-year time lag. CITATION: Magnusson Hanson LL; Åkerstedt T; Näswall K; Leineweber C; Theorell T; Westerlund H. Cross-lagged relationships between workplace demands, control, support, and sleep problems.

  • 67. Mallon, Lena
    et al.
    Broman, Jan-Erik
    Akerstedt, Torbjörn
    Stockholm University, Faculty of Social Sciences, Stress Research Institute.
    Hetta, Jerker
    Insomnia in Sweden: a population-based survey2014In: Sleep Disorders, ISSN 2090-3545, E-ISSN 2090-3553, Vol. 2014, p. 843126-Article in journal (Refereed)
    Abstract [en]

    Aims. Estimate the prevalence of insomnia and examine effects of sex, age, health problems, sleep duration, need for treatment, and usage of sleep medication. Methods. A sample of 1,550 subjects aged 18-84 years was selected for a telephone interview. The interview was completed by 1,128 subjects (72.8%). Results. 24.6% reported insomnia symptoms. Insomnia disorder, that is, insomnia symptoms and daytime consequences, was reported by 10.5%. The prevalence was similar among all age groups, with the exception of women aged 40-49 years who demonstrated a significantly higher prevalence, 21.6%. Having at least one physical or psychiatric disorder was reported by 82.8% of subjects with insomnia disorder. Mean sleep duration for subjects with insomnia disorder was 5.77 hours on weeknights and 7.03 hours on days off/weekends. The corresponding figures for subjects without insomnia disorder were 7.04 hours and 7.86 hours, respectively. Among those with insomnia disorder 62.5% expressed a need for treatment, and 20.0% used prescribed sleep medication regularly. Conclusions. Insomnia disorder is highly prevalent in the population. There are significant associations between insomnia disorder and physical and psychiatric disorders. A majority of subjects with insomnia disorder expressed a need for treatment, indicating a public health problem.

  • 68. Miley-Akerstedt, Anna
    et al.
    Jelic, Vesna
    Marklund, Kristina
    Walles, Håkan
    Åkerstedt, Torbjörn
    Stockholm University, Faculty of Social Sciences, Stress Research Institute. Karolinska Institute, Sweden.
    Hagman, Goran
    Andersson, Christin
    Lifestyle Factors Are Important Contributors to Subjective Memory Complaints among Patients without Objective Memory Impairment or Positive Neurochemical Biomarkers for Alzheimer's Disease2018In: Dementia and geriatric cognitive disorders extra, E-ISSN 1664-5464, Vol. 8, no 3, p. 439-452Article in journal (Refereed)
    Abstract [en]

    Background/Aims: Many patients presenting to a memory disorders clinic for subjective memory complaints do not show objective evidence of decline on neuropsychological data, have nonpathological biomarkers for Alzheimer's disease, and do not develop a neurodegenerative disorder. Lifestyle variables, including subjective sleep problems and stress, are factors known to affect cognition. Little is known about how these factors contribute to patients' subjective sense of memory decline. Understanding how lifestyle factors are associated with the subjective sense of failing memory that causes patients to seek a formal evaluation is important both for diagnostic workup purposes and for finding appropriate interventions and treatment for these persons, who are not likely in the early stages of a neurodegenerative disease. The current study investigated specific lifestyle variables, such as sleep and stress, to characterize those patients that are unlikely to deteriorate cognitively. Methods: Two hundred nine patients (mean age 58 years) from a university hospital memory disorders clinic were included. Results: Sleep problems and having much to do distinguished those with subjective, but not objective, memory complaints and non-pathological biomarkers for Alzheimer's disease. Conclusions: Lifestyle factors including sleep and stress are useful in characterizing subjective memory complaints from objective problems. Inclusion of these variables could potentially improve health care utilization efficiency and guide interventions.

  • 69. Miley-Åkerstedt, Anna
    et al.
    Hetta, Jerker
    Åkerstedt, Torbjorn
    Stockholm University, Faculty of Social Sciences, Stress Research Institute. Karolinska Institute, Sweden.
    Criteria for self-reported quantitative sleep characteristics of individuals who sought medical help for disturbed sleep - a survey of a representative sample of the Swedish population2018In: Nature and Science of Sleep, ISSN 1179-1608, Vol. 10, p. 295-301Article in journal (Refereed)
    Abstract [en]

    Background: The public often seeks rule-of-thumb criteria for good or poor sleep, with a particular emphasis on sleep duration, sleep latency, and the number of awakenings each night. However, very few criteria are available. Aim: The present study sought to identify such criteria. Methods: Whether or not a person has sought medical help for sleep problems was selected as an indicator of poor sleep. The group that was studied constituted a representative sample of the general Swedish population (N=1,128), with a response rate of 72.8%. Results: Logistic regression analysis, with an adjustment for age and gender, showed an increased OR for a weekday sleep duration of <= 6 hour, (OR >2, and for <5 hour: OR >6). For weekend sleep, the value was <= 6 hour (OR >2). For awakenings per night, the critical value was >= 2 (OR >2, and for awakenings: OR >9), and for a sleep latency the critical value was >= 30 minutes (OR >2, and for >= 45 minutes: OR >6). Adding difficulties falling asleep and early morning awakening (considered qualitative because of the reflected difficulty), led to the elimination of all the quantitative variables, except for the number of awakenings. The addition of negative effects on daytime functioning and sleep being a big problem resulted in the elimination of all the other predictors except age. Conclusion: It was concluded that weekday sleep <= 6 hour, >= 2 awakenings/night, and a sleep latency of >= 30 minutes, can function as criteria for poor sleep, but that qualitative sleep variables take over the role of quantitative ones, probably because they represent the integration of quantitative indicators of sleep.

  • 70.
    Nilsonne, G.
    et al.
    Karolinska Institutet, Sweden.
    Tamm, S.
    Karolinska Institutet, Sweden.
    Schwarz, J.
    Stockholm University, Faculty of Social Sciences, Stress Research Institute.
    Almeida, R.
    Fischer, H.
    Stockholm University, Faculty of Social Sciences, Department of Psychology, Biological psychology.
    Kecklund, G.
    Stockholm University, Faculty of Social Sciences, Stress Research Institute.
    Lekander, M.
    Karolinska Institutet, Sweden.
    Fransson, P.
    Åkerstedt, T.
    Stockholm University, Faculty of Social Sciences, Stress Research Institute.
    Increased global FMRI signal variability after partial sleep deprivation: Findings from the Stockholm sleepy brain study2017Conference paper (Refereed)
    Abstract [en]

    Introduction: Neural correlates of sleep deprivation are not fully understood and the difference between young and older adults in this regard has received little attention. We aimed to investigate the effect of partial sleep deprivation on resting state connectivity.

    Methods: 30 younger (20–30 years) and 23 older (65–75 years) healthy participants underwent MR imaging after normal sleep and partial sleep deprivation (3 h sleep). We acquired two runs of eyes-open resting state functional magnetic resonance images. Participants were monitored with eye-tracking to ensure their eyes remained open during scanning.

    Results: Global signal variability, defined as log-transformed standard deviation of average gray matter signal, was increased following partial sleep deprivation (0.16 [0.07, 0.24], p = 0.0004). In contrast to previous studies, we did not find that partial sleep deprivation inhibited connectivity in the default mode network, nor in other major networks investigated.

    Conclusion: Sleep deprivation caused increased global signal variability. This novel finding should be confirmed using independent data. Our finding of no difference in default mode connectivity in the sleep deprived state, could possibly be due to stricter monitoring of participants’ wakefulness compared to some earlier studies.

  • 71.
    Nilsonne, Gustav
    et al.
    Stockholm University, Faculty of Social Sciences, Stress Research Institute. Karolinska Institutet, Sweden.
    Lekander, Mats
    Stockholm University, Faculty of Social Sciences, Stress Research Institute. Karolinska Institutet, Sweden.
    Åkerstedt, Torbjörn
    Stockholm University, Faculty of Social Sciences, Stress Research Institute. Karolinska Institutet, Sweden.
    Axelsson, John
    Stockholm University, Faculty of Social Sciences, Stress Research Institute. Karolinska Institutet, Sweden.
    Ingre, Michael
    Stockholm University, Faculty of Social Sciences, Stress Research Institute.
    Diurnal Variation of Circulating Interleukin-6 in Humans: A Meta-Analysis2016In: PLoS ONE, ISSN 1932-6203, E-ISSN 1932-6203, Vol. 11, no 11, article id e0165799Article in journal (Refereed)
    Abstract [en]

    The pleiotropic cytokine interleukin-6 (IL-6) has been proposed to contribute to circadian regulation of sleepiness by increasing in the blood at night. Earlier studies have reported diurnal variation of IL-6, but phase estimates are conflicting. We have therefore performed a meta-analysis on the diurnal variation of circulating IL-6. Studies were included if they reported IL-6 in plasma or serum recorded at least twice within 24 hours in the same individual. A systematic search resulted in the inclusion of 43 studies with 56 datasets, for a total of 1100 participants. Individual participant data were available from 4 datasets with a total of 56 participants. Mixed-effects meta-regression modelling confirmed that IL-6 varied across the day, the most conspicuous effect being a trough in the morning. These results stand in contrast to earlier findings of a peak in the evening or night, and suggest that diurnal variation should be taken into account in order to avoid confounding by time of day in studies of IL-6 in plasma or serum.

  • 72.
    Nilsonne, Gustav
    et al.
    Stockholm University, Faculty of Social Sciences, Stress Research Institute.
    Tamm, Sandra
    Stockholm University, Faculty of Social Sciences, Stress Research Institute.
    D'Onofrio, Paolo
    Stockholm University, Faculty of Social Sciences, Stress Research Institute.
    Schwarz, Johanna F. A.
    Stockholm University, Faculty of Social Sciences, Stress Research Institute.
    Kecklund, Göran
    Stockholm University, Faculty of Social Sciences, Stress Research Institute.
    Åkerstedt, Torbjörn
    Stockholm University, Faculty of Social Sciences, Stress Research Institute.
    Fischer, Frida M.
    Lekander, Mats
    Stockholm University, Faculty of Social Sciences, Stress Research Institute.
    Effect of partial sleep deprivation on self-rated health and sickness2013Conference paper (Other academic)
  • 73.
    Nilsonne, Gustav
    et al.
    Stockholm University, Faculty of Social Sciences, Stress Research Institute. Karolinska Institutet, Sweden.
    Tamm, Sandra
    Karolinska Institutet, Sweden.
    D'Onofrio, Paolo
    Stockholm University, Faculty of Social Sciences, Stress Research Institute.
    Schwarz, Johanna
    Stockholm University, Faculty of Social Sciences, Stress Research Institute.
    Kecklund, Göran
    Stockholm University, Faculty of Social Sciences, Stress Research Institute.
    Lekander, Mats
    Stockholm University, Faculty of Social Sciences, Stress Research Institute. Karolinska Institutet, Sweden.
    Åkerstedt, Torbjörn
    Stockholm University, Faculty of Social Sciences, Stress Research Institute. Karolinska Institutet, Sweden.
    Fischer, Håkan
    Karolinska Institutet, Sweden.
    Detection of facial mimicry by electromyography during fMRI scanning2013Conference paper (Other academic)
    Abstract [en]

    We investigated whether electromyography (EMG) could be used to detect facial mimicry during fMRI scanning.

    EMG activity in the superciliary corrugator muscle increased when participants viewed angry faces.

  • 74.
    Nilsonne, Gustav
    et al.
    Stockholm University, Faculty of Social Sciences, Stress Research Institute.
    Tamm, Sandra
    Stockholm University, Faculty of Social Sciences, Stress Research Institute.
    D'Onofrio, Paolo
    Stockholm University, Faculty of Social Sciences, Stress Research Institute.
    Thuné, Hanna
    Stockholm University, Faculty of Social Sciences, Stress Research Institute.
    Schwarz, Johanna F A
    Stockholm University, Faculty of Social Sciences, Stress Research Institute.
    Petrovic, P
    Fischer, H
    Kecklund, Göran
    Stockholm University, Faculty of Social Sciences, Stress Research Institute.
    Åkerstedt, Torbjörn
    Stockholm University, Faculty of Social Sciences, Stress Research Institute.
    Lekander, Mats
    Stockholm University, Faculty of Social Sciences, Stress Research Institute.
    Effect of partial sleep deprivation on empathy for pain in an fMRI experiment2014Conference paper (Refereed)
  • 75.
    Nilsonne, Gustav
    et al.
    Stockholm University, Faculty of Social Sciences, Stress Research Institute.
    Tamm, Sandra
    Stockholm University, Faculty of Social Sciences, Stress Research Institute.
    D'Onofrio, Paolo
    Stockholm University, Faculty of Social Sciences, Stress Research Institute.
    Thuné, Hanna
    Stockholm University, Faculty of Social Sciences, Stress Research Institute.
    Schwarz, Johanna F A
    Stockholm University, Faculty of Social Sciences, Stress Research Institute.
    Petrovic, P
    Fischer, Håkan
    Kecklund, Göran
    Stockholm University, Faculty of Social Sciences, Stress Research Institute.
    Åkerstedt, Torbjörn
    Stockholm University, Faculty of Social Sciences, Stress Research Institute.
    Lekander, Mats
    Stockholm University, Faculty of Social Sciences, Stress Research Institute.
    Effect of partial sleep deprivation on empathy for pain in an fMRI experiment2014Conference paper (Other academic)
  • 76.
    Nilsonne, Gustav
    et al.
    Stockholm University, Faculty of Social Sciences, Stress Research Institute. Karolinska Institutet, Sweden.
    Tamm, Sandra
    Stockholm University, Faculty of Social Sciences, Stress Research Institute. Karolinska Institutet, Sweden.
    Månsson, Kristoffer N. T.
    Åkerstedt, Torbjörn
    Stockholm University, Faculty of Social Sciences, Stress Research Institute. Karolinska Institutet, Sweden.
    Lekander, Mats
    Stockholm University, Faculty of Social Sciences, Stress Research Institute. Karolinska Institutet, Sweden.
    Leukocyte telomere length and hippocampus volume: a meta-analysis [version 1; referees: 2 approved]2015In: F1000 Research, E-ISSN 2046-1402, Vol. 4, article id 1073Article, review/survey (Refereed)
    Abstract [en]

    Leukocyte telomere length has been shown to correlate to hippocampus volume, but effect estimates differ in magnitude and are not uniformly positive. This study aimed primarily to investigate the relationship between leukocyte telomere length and hippocampus gray matter volume by meta-analysis and secondarily to investigate possible effect moderators. Five studies were included with a total of 2107 participants, of which 1960 were contributed by one single influential study. A random-effects meta-analysis estimated the effect to r = 0.12 [95% CI -0.13, 0.37] in the presence of heterogeneity and a subjectively estimated moderate to high risk of bias. There was no evidence that apolipoprotein E (APOE) genotype was an effect moderator, nor that the ratio of leukocyte telomerase activity to telomere length was a better predictor than leukocyte telomere length for hippocampus volume. This meta-analysis, while not proving a positive relationship, also is not able to disprove the earlier finding of a positive correlation in the one large study included in analyses. We propose that a relationship between leukocyte telomere length and hippocamus volume may be mediated by transmigrating monocytes which differentiate into microglia in the brain parenchyma.

  • 77.
    Nilsonne, Gustav
    et al.
    Karolinska Institutet, Sweden.
    Tamm, Sandra
    Karolinska Institutet, Sweden.
    Schwarz, Johanna
    Stockholm University, Faculty of Social Sciences, Stress Research Institute.
    Almeida, Rita
    Fischer, Håkan
    Stockholm University, Faculty of Social Sciences, Department of Psychology, Biological psychology.
    Kecklund, Göran
    Stockholm University, Faculty of Social Sciences, Stress Research Institute.
    Lekander, Mats
    Stockholm University, Faculty of Social Sciences, Stress Research Institute.
    Fransson, Peter
    Åkerstedt, Torbjörn
    Karolinska Institutet, Sweden.
    Intrinsic brain connectivity after partial sleep deprivation in young and older adults2017Conference paper (Refereed)
    Abstract [en]

    Introduction: Sleep deprivation has been reported to affect intrinsic brain connectivity, notably in the default mode network, but studies to date have shown inconsistent effects and have largely included young participants. We therefore aimed to investigate effects of partial sleep deprivation on intrinsic brain connectivity in young and older participants. Methods: Participants aged 20-30 (n = 30) and 65-75 (n = 23) years underwent partial sleep deprivation (3 h sleep) in a cross-over design, with two eyes-open resting state functional magnetic resonance imaging (fMRI) runs in each session. We assessed intrinsic brain connectivity using independent components analysis (ICA) as well as seed-region analyses of functional connectivity, and also analysed global signal variability, regional homogeneity, and the amplitude of low-frequency fluctuations. Participants were monitored with eye-tracking to ensure they did not fall asleep during scanning. Results: Sleep deprivation caused increased global signal variability, defined as log-transformed standard deviation of average gray matter signal (0.16 [0.07, 0.24], p = 0.0004). In contrast to previous studies, sleep deprivation did not cause major changes in investigated resting state networks, nor did it cause changes in regional homogeneity. Younger participants had higher functional connectivity in most examined resting state networks, as well as higher regional homogeneity in brain areas including anterior and posterior cingulate cortex. Conclusions: We show for the first time that partial sleep deprivation caused increased global signal variability. This outcome should be examined as a potential biomarker for sleepiness using independent data. Unlike a few earlier studies, we did not find less default mode connectivity in the sleep deprived state, possibly because of stricter monitoring of participants' wakefulness.

  • 78.
    Nilsonne, Gustav
    et al.
    Stockholm University, Faculty of Social Sciences, Stress Research Institute. Karolinska Institutet, Sweden .
    Tamm, Sandra
    Stockholm University, Faculty of Social Sciences, Stress Research Institute. Karolinska Institutet, Sweden .
    Schwarz, Johanna
    Stockholm University, Faculty of Social Sciences, Stress Research Institute. Karolinska Institutet, Sweden .
    Almeida, Rita
    Fischer, Håkan
    Stockholm University, Faculty of Social Sciences, Department of Psychology, Biological psychology.
    Kecklund, Göran
    Stockholm University, Faculty of Social Sciences, Stress Research Institute.
    Lekander, Mats
    Stockholm University, Faculty of Social Sciences, Stress Research Institute. Karolinska Institutet, Sweden .
    Fransson, Peter
    Åkerstedt, Torbjörn
    Stockholm University, Faculty of Social Sciences, Stress Research Institute. Karolinska Institutet, Sweden .
    Intrinsic brain connectivity after partial sleep deprivation in young and older adults: results from the Stockholm Sleepy Brain study2017In: Scientific Reports, ISSN 2045-2322, E-ISSN 2045-2322, Vol. 7, article id 9422Article in journal (Refereed)
    Abstract [en]

    Sleep deprivation has been reported to affect intrinsic brain connectivity, notably reducing connectivity in the default mode network. Studies to date have however shown inconsistent effects, in many cases lacked monitoring of wakefulness, and largely included young participants. We investigated effects of sleep deprivation on intrinsic brain connectivity in young and older participants. Participants aged 20–30 (final n = 30) and 65–75 (final n = 23) years underwent partial sleep deprivation (3 h sleep) in a cross-over design, with two 8-minutes eyes-open resting state functional magnetic resonance imaging (fMRI) runs in each session, monitored by eye-tracking. We assessed intrinsic brain connectivity using independent components analysis (ICA) as well as seed-region analyses of functional connectivity, and also analysed global signal variability, regional homogeneity, and the amplitude of low-frequency fluctuations. Sleep deprivation caused increased global signal variability. Changes in investigated resting state networks and in regional homogeneity were not statistically significant. Younger participants had higher connectivity in most examined networks, as well as higher regional homogeneity in areas including anterior and posterior cingulate cortex. In conclusion, we found that sleep deprivation caused increased global signal variability, and we speculate that this may be caused by wake-state instability.

  • 79. Nordin, M.
    et al.
    Åkerstedt, Torbjorn
    Stockholm University, Faculty of Social Sciences, Stress Research Institute.
    Nordin, S.
    Psychometric evaluation and normative data for the Karolinska Sleep Questionnaire2013In: Sleep and Biological Rhythms, ISSN 1446-9235, E-ISSN 1479-8425, Vol. 11, no 4, p. 216-226Article in journal (Refereed)
    Abstract [en]

    The study objective was to validate the Karolinska Sleep Questionnaire with regard to dimensionality, internal consistency, and construct and criterion validity. Another objective was to provide normative data. Data from the cross-sectional Vasterbotten Environmental Health Study in Sweden were used. The 3406 participants in this study, 18 to 79 years old, constituted a random sample stratified for age and sex. Along with the Karolinska Sleep Questionnaire, the participants responded to the Hospital Anxiety and Depression Scale, the Perceived Stress Scale, and the Shirom Melamed Burnout Questionnaire for assessing construct validity. Factor analyses of the questions in the Karolinska Sleep Questionnaire that relate to nocturnal sleep revealed the dimensions sleep quality, non-restorative sleep, and sleep apnea. A separate factor analysis on the questions regarding day time sleepiness revealed a sleepiness dimension. The sleep quality, non-restorative sleep, and sleepiness dimensions showed approximate normal distributions, whereas the distribution for sleep apnea was positively skewed. All dimensions showed good internal consistency. Satisfactory construct validity was found for all dimensions. Using the DSM-IV criteria of insomnia, relevant questions in the Karolinska Sleep Questionnaire were combined into an index of nocturnal symptoms of insomnia as were questions of sleep apnea. Prevalences of insomnia and sleep apnea correspond well to those of other studies, indicating good criterion validity. The favorable psychometric properties of the dimensions and indexes from the Karolinska Sleep Questionnaire suggest their use for assessing sleep quality, non-restorative sleep, sleep apnea, sleepiness and nocturnal symptoms of insomnia.

  • 80. Nordin, Maria
    et al.
    Westerholm, Peter
    Alfredsson, Lars
    Åkerstedt, Torbjörn
    Stockholm University, Faculty of Social Sciences, Stress Research Institute.
    Social support and sleep. Longitudinal relationships from the WOLF-Study2012In: Psychology, ISSN 2152-7180, E-ISSN 2152-7199, Vol. 3, no 12A, p. 1223-1230Article in journal (Refereed)
    Abstract [en]

    Aim: To investigate the relationship between two social support dimensions (network and emotional support) and sleep quality and between two social support sources (at and outside work) and sleep quality. Methods: The three-wave prospective Work Lipids and Fibrinogen (WOLF) study from Northern Sweden was used including 2420 participants who had filled out a questionnaire on working life, life style and health. Sleep quality was assessed by the Karolinska Sleep Questionnaire (KSQ). Structure and function of social support were measured as network support both at and outside work by Availability of Social Integration (AVSI) and emotional support both at and outside work by Availability of Attachment (AVAT). Logistic regression was used, utilizing variables created to assess development over time. Moreover, reversed causation was tested. Results: Improved network support at work decreased the risk of disturbed sleep (OR .65; 95% CI .47 - .90) as did improved emotional support outside work (OR .69; 95% CI .49 - .96). Reporting a constant poor network support at work increased the risk of disturbed sleep (OR 1.53, 95% CI 1.10 - 2.11) as did reporting a constant poor emotional support outside work (OR 1.46; 95% CI 1.02 - 2.05). In men constant good network at work decreased the risk of disturbed sleep (OR .49, 95% CI .34 - .71). Reversed causation analyses indicate some bi-directionality. Conclusion: Being able to perceive social support is a human strength promoting sleep. Both dimension (structure and function) and source (at and outside work) of support matters in sleep quality and seem to be related since the structural dimension was more likely to affect sleep when derived from work, whereas the functional dimension affected sleep quality if it was provided outside work. Men’s sleep seems to be more sensitive to network support at work. Disturbed sleep may also alter the perception of social support.

  • 81.
    Osmanovic-Thunström, Almira
    et al.
    Stockholm University, Faculty of Social Sciences, Aging Research Center (ARC), (together with KI).
    Mossello, Enrico
    Åkerstedt, Torbjörn
    Stockholm University, Faculty of Social Sciences, Stress Research Institute.
    Fratiglioni, Laura
    Stockholm University, Faculty of Social Sciences, Aging Research Center (ARC), (together with KI). Stockholm Gerontology Research Center, Sweden.
    Wang, Hui-Xin
    Stockholm University, Faculty of Social Sciences, Aging Research Center (ARC), (together with KI).
    Do levels of perceived stress increase with increasing age after age 65? A population-based study2015In: Age and Ageing, ISSN 0002-0729, E-ISSN 1468-2834, Vol. 44, no 5, p. 828-834Article in journal (Refereed)
    Abstract [en]

    Methods: a dementia-free cohort of 1,656 adults aged 66-97 years living at home or in institutions, participating in the Swedish National Aging and Care study, Kungsholmen (SNAC-K) was assessed for levels of perceived stress using the 10-item perceived stress scale (PSS).

    Results: prevalence of high stress according to the top tertile of the population (PSS score 20+) was 7.8% in adults aged 81+ years, 7.5% in adults aged 72-78 and 6.2% in adults aged 66 years (P = 0.020). More women than men reported high stress, 8.3 versus 5.4% (P = 0.001). Levels of stress increased with increasing age (P = 0.001) in the linear regression model. This association remained after adjustment for demographic and psychosocial factors, but no longer was present after adjusting for health-related factors.

    Conclusion: health-related stress is highly prevalent in older adults and seems to play an important role in the association between levels of perceived stress and age in older adults.

  • 82. Paanalahti, Kari
    et al.
    Wertli, Maria M.
    Held, Ulrike
    Åkerstedt, Torbjörn
    Stockholm University, Faculty of Social Sciences, Stress Research Institute. Karolinska Institutet, Sweden.
    Holm, Lena W.
    Nordin, Margareta
    Skillgate, Eva
    Spinal pain-good sleep matters: a secondary analysis of a randomized controlled trial2016In: European spine journal, ISSN 0940-6719, E-ISSN 1432-0932, Vol. 25, no 3, p. 760-765Article in journal (Refereed)
    Abstract [en]

    Purpose

    The estimated prevalence of poor sleep in patients with non-specific chronic low back pain is estimated to 64 % in the adult population. The annual cost for musculoskeletal pain and reported poor sleep is estimated to be billions of dollars annually in the US. The aim of this cohort study with one-year follow-up was to explore the role of impaired sleep with daytime consequence on the prognosis of non-specific neck and/or back pain.

    Methods

    Secondary analysis of a randomized controlled trial, including 409 patients.

    Results

    Patients with good sleep at baseline were more likely to experience a minimal clinically important difference in pain [OR 2.03 (95 % CI 1.22–3.38)] and disability [OR 1.85 (95 % CI 1.04–3.30)] compared to patients with impaired sleep at one-year follow-up.

    Conclusion

    Patients with non-specific neck and/or back pain and self-reported good sleep are more likely to experience a minimal clinically important difference in pain and disability compared to patients with impaired sleep with daytime consequence.

  • 83.
    Petersen, Helena
    et al.
    Stockholm University, Faculty of Social Sciences, Stress Research Institute.
    Kecklund, Göran
    Stockholm University, Faculty of Social Sciences, Stress Research Institute.
    D'Onofrio, Paolo
    Stockholm University, Faculty of Social Sciences, Stress Research Institute.
    Akerstedt, Torbjörn
    Stockholm University, Faculty of Social Sciences, Stress Research Institute.
    Exercise is associated with changes in sleep architecture during stress2014In: Journal of Sleep Research, ISSN 0962-1105, E-ISSN 1365-2869, Vol. 23, no Suppl. 1Article in journal (Other academic)
  • 84.
    Petersen, Helena
    et al.
    Stockholm University, Faculty of Social Sciences, Stress Research Institute. Karolinska Institutet, Sweden.
    Kecklund, Göran
    Stockholm University, Faculty of Social Sciences, Stress Research Institute. Karolinska Institutet, Sweden.
    D'Onofrio, Paolo
    Stockholm University, Faculty of Social Sciences, Stress Research Institute.
    Axelsson, John
    Stockholm University, Faculty of Social Sciences, Stress Research Institute. Karolinska Institutet, Sweden.
    Åkerstedt, Torbjörn
    Stockholm University, Faculty of Social Sciences, Stress Research Institute. Karolinska Institutet, Sweden.
    Thank god it's Friday - sleep improved2017In: Journal of Sleep Research, ISSN 0962-1105, E-ISSN 1365-2869, Vol. 26, no 5, p. 567-571Article in journal (Refereed)
    Abstract [en]

    The weekend is usually seen as a window of recovery. Thus, sleep before a day off may be less impaired than that before a workday. However, very few polysomnographical studies have investigated this hypothesis. Therefore, the aim of the present study was to compare sleep before a workday with that before a weekend. Seventeen teachers participated. Sleep was recorded with polysomnography on one weekday night during the workweek, and on a workday (Friday) followed by a day off. Sleep diaries and actigraphs were also used. Weekend sleep showed delayed bedtime and time of rising, a longer total sleep time (45 min), increased N3 and N1, and decreased N2 and REM. Sleep spindles were reduced. The results remained after truncation to the shortest common sleep duration (5 h). The increase in N3 from weekday sleep to Friday night sleep was positively correlated with N1 change (r = 0.853, P <= 0.001), and negatively correlated with N2 change (r = -0.614, P <= 0.001). Subjective ratings showed that weekend sleep was associated with less awakening problems and lower subjective arousal during the day. The authors concluded that weekend sleep was longer, and showed increased N3 and N1. The authors suggest that the N3 increase before the day off is a result of lower stress, while the N1 increase may be an effect of sleep spindle suppression via the increase of N3 (which would suppress sleep spindles), thus reducing N2 and enhancing N1.

  • 85.
    Petersen, Helena
    et al.
    Stockholm University, Faculty of Social Sciences, Stress Research Institute. Karolinska Institutet, Sweden.
    Kecklund, Göran
    Stockholm University, Faculty of Social Sciences, Stress Research Institute.
    D'Onofrio, Paolo
    Stockholm University, Faculty of Social Sciences, Stress Research Institute.
    Nilsson, Jens
    Stockholm University, Faculty of Social Sciences, Stress Research Institute.
    Åkerstedt, Torbjörn
    Stockholm University, Faculty of Social Sciences, Stress Research Institute. Karolinska Institutet, Sweden.
    Stress vulnerability and the effects of moderate daily stress on sleep polysomnography and subjective sleepiness2013In: Journal of Sleep Research, ISSN 0962-1105, E-ISSN 1365-2869, Vol. 22, no 1, p. 50-57Article in journal (Refereed)
    Abstract [en]

    The purpose of this study was to investigate if and how sleep physiology is affected by naturally occurring high work stress and identify individual differences in the response of sleep to stress. Probable upcoming stress levels were estimated through weekly web questionnaire ratings. Based on the modified FIRST-scale (Ford insomnia response to stress) participants were grouped into high (n = 9) or low (n = 19) sensitivity to stress related sleep disturbances (Drake et al., 2004). Sleep was recorded in 28 teachers with polysomnography, sleep diaries and actigraphs during one high stress and one low stress condition in the participants home. EEG showed a decrease in sleep efficiency during the high stress condition. Significant interactions between group and condition were seen for REM sleep, arousals and stage transitions. The sensitive group had an increase in arousals and stage transitions during the high stress condition and a decrease in REM, whereas the opposite was seen in the resilient group. Diary ratings during the high stress condition showed higher bedtime stress and lower ratings on the awakening index (insufficient sleep and difficulties awakening). Ratings also showed lower cognitive function and preoccupation with work thoughts in the evening. KSS ratings of sleepiness increased during stress for the sensitive group. Saliva samples of cortisol showed no effect of stress. It was concluded that moderate daily stress is associated with a moderate negative effect on sleep sleep efficiency and fragmentation. A slightly stronger effect was seen in the sensitive group.

  • 86.
    Petersen, Helena
    et al.
    Stockholm University, Faculty of Social Sciences, Stress Research Institute.
    Kecklund, Göran
    Stockholm University, Faculty of Social Sciences, Stress Research Institute.
    D'Onofrio, Paolo
    Stockholm University, Faculty of Social Sciences, Stress Research Institute.
    Åkerstedt, Torbjörn
    Stockholm University, Faculty of Social Sciences, Stress Research Institute.
    Exercise is associated with changes in sleep architecture during stress2014Conference paper (Other academic)
  • 87. Philip, Pierre
    et al.
    Chaufton, Cyril
    Orriols, Ludivine
    Lagarde, Emmanuel
    Amoros, Emmanuelle
    Laumon, Bernard
    Åkerstedt, Torbjörn
    Stockholm University, Faculty of Social Sciences, Stress Research Institute.
    Taillard, Jacques
    Sagaspe, Patricia
    Complaints of poor sleep and risk of traffic accidents: a population-based case-control study.2014In: PLoS ONE, ISSN 1932-6203, E-ISSN 1932-6203, Vol. 9, no 12, p. e114102-Article in journal (Refereed)
    Abstract [en]

    INTRODUCTION: This study aimed to determine the sleepiness-related factors associated with road traffic accidents.

    METHODS: A population based case-control study was conducted in 2 French agglomerations. 272 road accident cases hospitalized in emergency units and 272 control drivers matched by time of day and randomly stopped by police forces were included in the study. Odds ratios were calculated for the risk of road traffic accidents.

    RESULTS: As expected, the main predictive factor for road traffic accidents was having a sleep episode at the wheel just before the accident (OR 9.97, CI 95%: 1.57-63.50, p<0.05). The increased risk of traffic accidents was 3.35 times higher in subjects who reported very poor quality sleep during the last 3 months (CI 95%: 1.30-8.63, p<0.05), 1.69 times higher in subjects reporting sleeping 6 hours or fewer per night during the last 3 months (CI 95%: 1.00-2.85, p<0.05), 2.02 times higher in subjects reporting symptoms of anxiety or nervousness in the previous day (CI 95%: 1.03-3.97, p<0.05), and 3.29 times higher in subjects reporting taking more than 2 medications in the last 24 h (CI 95%: 1.14-9.44, p<0.05). Chronic daytime sleepiness measured by the Epworth Sleepiness Scale, expressed heavy snoring and nocturnal leg movements did not explain traffic accidents.

    CONCLUSION: Physicians should be attentive to complaints of poor sleep quality and quantity, symptoms of anxiety-nervousness and/or drug consumption in regular car drivers.

  • 88. Qvist, Ninni
    et al.
    Bergström, Ingrid
    Åkerstedt, Torbjörn
    Stockholm University, Faculty of Social Sciences, Stress Research Institute. Karolinska Institute, Stockholm.
    Persson, Jan
    Konradsen, Hanne
    Forss, Anette
    From being restrained to recapturing vitality: non-western immigrant women's experiences of undergoing vitamin D treatment after childbirth2019In: International Journal of Qualitative Studies on Health and Well-being, ISSN 1748-2623, E-ISSN 1748-2631, Vol. 14, no 1, article id 1632111Article in journal (Refereed)
    Abstract [en]

    Purpose: Vitamin D deficiency is a complex topic in human health and ill-health and has been studied in a variety of contexts and populations. Few studies examine Vitamin D deficiency among non-western immigrant women and even fewer examine women's perspective on daily life while living with low vitamin D levels after childbirth and undergoing vitamin D treatment. The aim was, therefore, to explore health and ill-health among non-western immigrant women living with low vitamin D levels after childbirth and reaching normalized levels after one year of vitamin D treatment.

    Method: An explorative qualitative study using qualitative content analysis. Six women aged 25 to 38 years, diagnosed with low 25-hydroxyvitamin D levels during pregnancy, were recruited after having undergone vitamin D treatment.

    Results: The women told about living a restrained life which gradually transformed into an experience of recaptured vitality. They also experienced a need for continuity in medication, as an interruption of treatment meant returning symptoms.

    Conclusion: In this study, non-western immigrant women described benefits in everyday life, increased strength, relieved pain and improved sleep quality. The findings can provide valuable knowledge for healthcare providers meeting women with physical weakness, musculoskeletal pain and/or poor sleep quality after childbirth. Further studies using a longitudinal design and larger samples are warranted.

  • 89.
    Ramberg, Joacim
    et al.
    Stockholm University, Faculty of Social Sciences, Department of Public Health Sciences, Centre for Health Equity Studies (CHESS).
    Brolin Låftman, Sara
    Stockholm University, Faculty of Social Sciences, Department of Public Health Sciences, Centre for Health Equity Studies (CHESS).
    Åkerstedt, Torbjörn
    Stockholm University, Faculty of Social Sciences, Stress Research Institute.
    Modin, Bitte
    Stockholm University, Faculty of Social Sciences, Department of Public Health Sciences, Centre for Health Equity Studies (CHESS).
    Teacher Stress and Students’ School Well-being: the Case of Upper Secondary Schools in Stockholm2019In: Scandinavian Journal of Educational Research, ISSN 0031-3831, E-ISSN 1470-1170Article in journal (Refereed)
    Abstract [en]

    Stress and stress-related complaints such as fatigue and depressed mood are common among teachers. Yet, knowledge about the links between the overall level of teacher stress within a school and individual student outcomes is scarce. This study investigates if the levels of teacher-reported stress, fatigue and depressed mood within a school are associated with students’ ratings of their school satisfaction and perceived teacher caring, respectively. Data derives from two separate data collections performed in upper secondary schools in 2016, the Stockholm School Survey (SSS) and the Stockholm Teacher Survey (STS), which were linked together (5367 students and 1045 teachers in 46 schools). Two-level linear regression analyses were performed. Results showed negative associations between school-level teacher stress, fatigue, and depressed mood and students’ school satisfaction and perceived teacher caring, even when controlling for student- and school-level sociodemographic characteristics. The findings suggest that teacher stress may have negative implications for students.

  • 90. Rehman, Javaid-ur
    et al.
    Brismar, Kerstin
    Holmbäck, Ulf
    Åkerstedt, Torbjörn
    Stockholm University, Faculty of Social Sciences, Stress Research Institute.
    Axelsson, John
    Sleeping during the day: effects on the 24-h patterns of IGF-binding protein 1, insulin, glucose, cortisol, and growth hormone.2010In: European Journal of Endocrinology, ISSN 0804-4643, E-ISSN 1479-683X, Vol. 163, no 3, p. 383-90Article in journal (Refereed)
    Abstract [en]

    BACKGROUND: Disturbed sleep is a major risk factor for metabolic disturbances, including type 2 diabetes, but the involved mechanisms are still poorly understood. We investigated how an acute shift of sleep to the daytime affected IGF-binding protein 1 (IGFBP1), which is a risk factor for diabetes. METHODS: Seven healthy men (age, 22-32 years) participated in a night sleep condition (sleep 2300-0700 h) and a day sleep condition (0700-1500 h) with hourly blood samples taken for 25 h (starting at 1900 h) and isocaloric meals every 4th hour awake. The blood samples were analyzed for IGFBP1, insulin, GH, glucose, and cortisol. RESULT: The acute shift of sleep and meal timing (to 8 h) shifted the 24-h patterns of IGFBP1, glucose, insulin, and GH to a similar degree. However, the day sleep condition also resulted in elevated levels of IGFBP1 (area under curve (AUC)+22%, P<0.05), and reduced glucose levels (AUC-7%, P<0.05) compared with nocturnal sleep. Sleeping during the day resulted in elevated cortisol levels during early sleep and reduced levels in late sleep, but also in increased levels the subsequent evening (P's<0.05). CONCLUSION: Sleep-fasting seems to be the primary cause for the elevation of IGFBP1, irrespective of sleep timing. However, sleeping during the day resulted in higher levels of IGFBP1 than nocturnal sleep, suggesting altered metabolism among healthy individuals, which may have implications for other groups with altered sleep/eating habits such as shift workers. Moreover, sleep and meal times should be accounted for while interpreting IGFBP1 samples.

  • 91. Sallinen, Mikael
    et al.
    Sihvola, Maria
    Puttonen, Sampsa
    Ketola, Kimmo
    Tuori, Antti
    Härmä, Mikko
    Kecklund, Göran
    Stockholm University, Faculty of Social Sciences, Stress Research Institute.
    Åkerstedt, Torbjörn
    Karolinska Institute, Sweden.
    Sleep, alertness and alertness management among commercial airline pilots on short-haul and long-haul flights2016In: Accident Analysis and Prevention, ISSN 0001-4575, E-ISSN 1879-2057, Vol. 98, p. 320-329Article in journal (Refereed)
    Abstract [en]

    Airline pilots' sleep and on-duty alertness are important focus areas in commercial aviation. Until now, studies pertaining to this topic have mainly focused on specific characteristics of flights and thus a comprehensive picture of the matter is not well established. In addition, research knowledge of what airline pilots actually do to maintain their alertness while being on duty is scarce. To address these gaps in research knowledge, we conducted a field study on a representative sample of the airline pilots of a medium-sized airline. The sample consisted of 90 pilots, of whom 30 flew long-haul (LH) routes, 30 short-haul (SH) routes, and 30 flew both. A total of 86 pilots completed the measurements that lasted for almost two months per pilot. The measurements resulted in a total of 965 flight duty periods (FDPs) including SH flights and 627 FDPs including LH flights. During the measurement periods, sleep was measured by a diary and actigraphs, on-duty alertness by the Karolinska Sleepiness Scale (KSS) in all flight phases, and on-duty alertness management strategies by the diary. Results showed that SH and LH FDPs covering the whole domicile night (00:00-06:00 at home base) were most consistently associated with reduced sleep-wake ratio and subjective alertness. Approximately every 3rd FDP falling into this category involved a reduced sleep-wake ratio (1:3 or lower) and every 2nd a reduced level of subjective alertness (KSS rating 8-9 in at least one flight phase). The corresponding frequencies for the SH and LH FDPs that partly covered the domicile night were every 10th and every 5th FDP and for the pure non-night FDPs every 30th and every 36th FDP, respectively. The results also showed that the pilots tended to increase the use of effective on-duty alertness management strategies (consuming alertness-promoting products and taking strategic naps) in connection with the FDPs that overlapped the domicile night. Finally, the results showed that the frequency of flights involving reduced subjective alertness depended on how alertness was assessed. If it was assessed solely in the flight phase just before starting the landing procedures (top of descent) the phenomenon was less frequent than if the preceding cruise phase was also taken into account. Our results suggest that FDPs covering the whole domicile night should be prioritised over the other FDPs in fatigue management, regardless of whether an FDP is a short-haul or a long-haul. In addition, the identification of fatigue in flight operations requires one to assess pilots' alertness across all flight phases, not only at ToD. Due to limitations in our data, these conclusions can, however, be generalise to only LH FDPs during which pilots can be expected to be well acclimatised to the local time at their home base and SH night FDPs that include at least 3h of flying in the cruise phase.

  • 92. Sandberg, David
    et al.
    Anund, Anna
    Fors, Carina
    Kecklund, Göran
    Stockholm University, Faculty of Social Sciences, Stress Research Institute.
    Karlsson, Johan G.
    Wahde, Mattias
    Åkerstedt, Torbjörn
    Stockholm University, Faculty of Social Sciences, Stress Research Institute.
    The characteristics of sleepiness during real driving at night - a study of driving performance, physiology and subjective experience2011In: Sleep, ISSN 0161-8105, E-ISSN 1550-9109, Vol. 34, no 10, p. 1317-25Article in journal (Refereed)
    Abstract [en]

    STUDY OBJECTIVES: Most studies of sleepy driving have been carried out in driving simulators. A few studies of real driving are available, but these have used only a few sleepiness indicators. The purpose of the present study was to characterize sleepiness in several indicators during real driving at night, compared with daytime driving.

    DESIGN: Participants drove 55 km (at 90km/h) on a 9-m-wide rural highway in southern Sweden. Daytime driving started at 09:00 or 11:00 (2 groups) and night driving at 01:00 or 03:00 (balanced design).

    SETTING: Instrumented car on a real road in normal traffic.

    PARTICIPANTS: Eighteen participants drawn from the local driving license register.

    INTERVENTIONS: Daytime and nighttime drives.

    MEASUREMENT AND RESULTS: The vehicle was an instrumented car with video monitoring of the edge of the road and recording of the lateral position and speed. Electroencephalography and electrooculography were recorded, together with ratings of sleepiness every 5 minutes. Pronounced effects of night driving were seen for subjective sleepiness, electroencephalographic indicators of sleepiness, blink duration, and speed. Also, time on task showed significant effects for subjective sleepiness, blink duration, lane position, and speed. Sleepiness was highest toward the end of the nighttime drive. Night driving caused a leftward shift in lateral position and a reduction of speed. The latter two findings, as well as the overall pattern of sleepiness indicators, provide new insights into the effects of night driving.

    CONCLUSION: Night driving is associated with high levels of subjective, electrophysiologic, and behavioral sleepiness. CITATION: Sandberg D; Anund A; Fors C; Kecklund G; Karlsson JG; Wahde M; Åkerstedt T. The characteristics of sleepiness during real driving at night-a study of driving performance, physiology and subjective experience. 

  • 93.
    Sandberg, David
    et al.
    Stockholm University, Faculty of Social Sciences, Stress Research Institute.
    Wadhe, Mattias
    Anund, Anna
    Kecklund, Göran
    Stockholm University, Faculty of Social Sciences, Stress Research Institute.
    Åkerstedt, Torbjörn
    Stockholm University, Faculty of Social Sciences, Stress Research Institute.
    The impact of sleepiness on lane positioning in truck drivers2013In: Driver Distraction and Inattention: Advances in Research and Countermeasures, Volume 1 / [ed] Michael A. Regan, John D. Lee, Trent W. Victor, Farnham: Ashgate, 2013, p. 405-416Chapter in book (Other academic)
    Abstract [en]

    This chapter concerns the detection of sleepiness in truck drivers. Data obtained from a driver sleepiness study involving real-world driving are used in order to analyse the performance of several sleepiness indicators based on driving behavior; such as, for example, variability in lateral position and heading angle. Contrary to the results obtained for passenger cars, for heavy trucks it is found that indicators based on variability provide little or no information; their performance does not rise significantly above chance levels. However, the data indicate that there is a significant difference in the average lane position for sleepy and alert drivers, respectively, such that a sleepy driver generally places the vehicle closer (by about 0.2 m) to the centre of the road than an alert driver. The analysis also shows a significant, monotonous, increase in average lateral position (measured from the right, outer, lane boundary towards the lane centre) between the four cases of (i) daytime alert driving, (ii) daytime sleepy driving, (iii) night-time alert driving and (iv) nighttime sleepy driving.

  • 94. Sandberg, David
    et al.
    Åkerstedt, Torbjörn
    Stockholm University, Faculty of Social Sciences, Stress Research Institute.
    Anund, Anna
    Kecklund, Göran
    Stockholm University, Faculty of Social Sciences, Stress Research Institute.
    Wahde, Mattias
    Detecting Driver Sleepiness Using Optimized Nonlinear Combinations of Sleepiness Indicators2011In: IEEE transactions on intelligent transportation systems (Print), ISSN 1524-9050, E-ISSN 1558-0016, Vol. 12, no 1, p. 97-108Article in journal (Refereed)
    Abstract [en]

    This paper addresses the problem of detecting sleepiness in car drivers. First, a variety of sleepiness indicators (based on driving behavior) proposed in the literature were evaluated. These indicators were then subjected to parametric optimization using stochastic optimization methods. To improve performance, the functional form of some of the indicators was generalized before optimization. Next, using a neural network, the best performing sleepiness indicators were combined with a mathematical model of sleepiness, i.e., the sleep/wake predictor (SWP). The analyses were based on data obtained from a study that involved 12 test subjects at the moving-base driving simulator at the Swedish National Road and Transportation Research Institute (VTI), Linkoping, Sweden. The data were derived from 12 1-h driving sessions for each test subject, with varying degrees of sleepiness. The performance measure (range [0,1]) for indicators was taken as the average of sensitivity and specificity. Starting with indicators proposed in the literature, the best such indicator, i.e., the standard deviation of the yaw angle, reached a performance score of 0.72 on previously unseen test data. It was found that indicators based on a given signal gave essentially equal performance after parametric optimization, but in no case was it better than 0.72. The best generalized indicator (the generic variability indicator) obtained a performance score of 0.74. SWP achieved a score of 0.78. However, by nonlinearly combining SWP with the generic variability indicator, a score of 0.83 was obtained. Thus, the results imply that a nonlinear combination of a measure based on driving behavior with a model of sleepiness significantly improves driver sleepiness detection.

  • 95.
    Schiller, Helena
    et al.
    Stockholm University, Faculty of Social Sciences, Stress Research Institute.
    Lekander, Mats
    Stockholm University, Faculty of Social Sciences, Stress Research Institute. Karolinska Institutet, Sweden.
    Rajaleid, Kristiina
    Stockholm University, Faculty of Social Sciences, Stress Research Institute. Stockholm University, Faculty of Social Sciences, Centre for Health Equity Studies (CHESS).
    Hellgren, Carina
    Åkerstedt, Torbjörn
    Stockholm University, Faculty of Social Sciences, Stress Research Institute. Karolinska Institutet, Sweden.
    Barck-Holst, Peter
    Kecklund, Göran
    Stockholm University, Faculty of Social Sciences, Stress Research Institute. Radboud University, The Netherlands.
    The impact of reduced worktime on sleep and perceived stress – a group randomized intervention study using diary data2017In: Scandinavian Journal of Work, Environment and Health, ISSN 0355-3140, E-ISSN 1795-990X, Vol. 43, no 2, p. 109-116Article in journal (Refereed)
    Abstract [en]

    Objective Insufficient time for recovery between workdays may cause fatigue and disturbed sleep. This study evaluated the impact of an intervention that reduced weekly working hours by 25% on sleep, sleepiness and perceived stress for employees within the public sector.

    Method Participating workplaces (N=33) were randomized into intervention and control groups. Participants (N=580, 76% women) worked full-time at baseline. The intervention group (N=354) reduced worktime to 75% with preserved salary during 18 months. Data were collected at baseline and after 9 and 18 months follow-up. Sleep quality, sleep duration, sleepiness, perceived stress,and worries and stress at bedtime were measured with diary during one week per data collection.

    Result A multilevel mixed model showed that compared with the control group, at the 18-month follow-up, the intervention group had improved sleep quality and sleep duration (+23 minutes) and displayed reduced levels of sleepiness, perceived stress, and worries and stress at bedtime on workdays (P<0.002). The same effects were shown for days off (P<0.006), except for sleep length. Effect sizes were small (Cohen’s f2<0.08). Adding gender, age, having children living at home, and baseline values of sleep quality and worries and stress at bedtime as additional between-group factors did not influence the results.

    Conclusion A 25% reduction of weekly work hours with retained salary resulted in beneficial effects on sleep, sleepiness and perceived stress both on workdays and days off. These effects were maintained over an 18-month period. This randomized intervention thus indicates that reduced worktime may improve recovery and perceived stress.

  • 96.
    Schiller, Helena
    et al.
    Stockholm University, Faculty of Social Sciences, Stress Research Institute.
    Lekander, Mats
    Stockholm University, Faculty of Social Sciences, Stress Research Institute. Karolinska Institutet, Sweden.
    Rajaleid, Kristiina
    Stockholm University, Faculty of Social Sciences, Stress Research Institute. Stockholm University, Faculty of Social Sciences, Centre for Health Equity Studies (CHESS).
    Hellgren, Carina
    Åkerstedt, Torbjörn
    Stockholm University, Faculty of Social Sciences, Stress Research Institute. Karolinska Institutet, Sweden.
    Barck-Holst, Peter
    Kecklund, Göran
    Stockholm University, Faculty of Social Sciences, Stress Research Institute. Radboud University, The Netherlands.
    Total workload and recovery in relation to worktime reduction – a randomized controlled intervention study with time-use dataManuscript (preprint) (Other academic)
    Abstract [en]

    Objectives: A 25% reduction of weekly work hours for full-time employees has been shown to improve sleep and alertness and reduce stress during both workdays and days off. The aim of the present study was to investigate how employees use their time during such an intervention: does total workload (paid and non-paid work) decrease, and recovery time increase, when work hours are reduced?

    Methods: Full-time employees within the public sector (N=636; 75% women) were randomized into intervention group and control group. The intervention group (N=370) reduced worktime to 75% with preserved salary during 18 months. Data were collected at baseline, after 9 months and 18 months. Time-use was reported every half hour daily between 06 and 01 a.m. during one week at each data collection. Data were analyzed with multilevel mixed modeling.

    Results: Compared to the control group, the intervention group increased the time spent on domestic work and relaxing hobby activities during workdays when worktime was reduced (p≤0.001). On days off, more time was spent in free-time activities (p=0.003). Total workload decreased (-65 minutes) and time spent in recovery activities increased on workdays (+53 minutes). The pattern of findings was similar in subgroups defined by gender, family status and job situation.

    Conclusions: A worktime reduction of 25% for full-time workers resulted in decreased total workload and an increase of time spent in recovery activities, which is in line with the suggestion that worktime reduction may be beneficial for long-term health and stress.

  • 97.
    Schiller, Helena
    et al.
    Stockholm University, Faculty of Social Sciences, Stress Research Institute.
    Lekander, Mats
    Stockholm University, Faculty of Social Sciences, Stress Research Institute. Karolinska Institutet, Sweden.
    Rajaleid, Kristiina
    Stockholm University, Faculty of Social Sciences, Stress Research Institute. Stockholm University, Faculty of Social Sciences, Centre for Health Equity Studies (CHESS).
    Hellgren, Carina
    Åkerstedt, Torbjörn
    Stockholm University, Faculty of Social Sciences, Stress Research Institute. Karolinska Institutet, Sweden.
    Barck-Holst, Peter
    Kecklund, Göran
    Stockholm University, Faculty of Social Sciences, Stress Research Institute. Radboud University, The Netherlands .
    Total workload and recovery in relation to worktime reduction: a randomised controlled intervention study with time-use data2018In: Occupational and Environmental Medicine, ISSN 1351-0711, E-ISSN 1470-7926, Vol. 75, no 3, p. 218-226Article in journal (Refereed)
    Abstract [en]

    Objectives A 25% reduction of weekly work hours for full-time employees has been shown to improve sleep and alertness and reduce stress during both workdays and days off. The aim of the present study was to investigate how employees use their time during such an intervention: does total workload (paid and non-paid work) decrease, and recovery time increase, when work hours are reduced?

    Methods Full-time employees within the public sector (n=636; 75% women) were randomised into intervention group and control group. The intervention group (n=370) reduced worktime to 75% with preserved salary during 18 months. Data were collected at baseline, after 9 months and 18 months. Time-use was reported every half-hour daily between 06:00 and 01:00 during 1 week at each data collection. Data were analysed with multilevel mixed modelling.

    Results Compared with the control group, the intervention group increased the time spent on domestic work and relaxing hobby activities during workdays when worktime was reduced (P≤0.001). On days off, more time was spent in free-time activities (P=0.003). Total workload decreased (-65 min) and time spent in recovery activities increased on workdays (+53 min). The pattern of findings was similar in subgroups defined by gender, family status and job situation.

    Conclusions A worktime reduction of 25% for full-time workers resulted in decreased total workload and an increase of time spent in recovery activities, which is in line with the suggestion that worktime reduction may be beneficial for long-term health and stress.

  • 98.
    Schwarz, Johanna
    et al.
    Stockholm University, Faculty of Social Sciences, Stress Research Institute. Karolinska Institutet, Sweden.
    Axelsson, John
    Stockholm University, Faculty of Social Sciences, Stress Research Institute. Karolinska Institutet, Sweden.
    Gerhardsson, Andreas
    Stockholm University, Faculty of Social Sciences, Department of Psychology, Work and organizational psychology.
    Tamm, Sandra
    Stockholm University, Faculty of Social Sciences, Stress Research Institute. Karolinska Institutet, Sweden.
    Fischer, Håkan
    Stockholm University, Faculty of Social Sciences, Department of Psychology, Biological psychology.
    Kecklund, Göran
    Stockholm University, Faculty of Social Sciences, Stress Research Institute. Karolinska Institutet, Sweden.
    Åkerstedt, Torbjörn
    Stockholm University, Faculty of Social Sciences, Stress Research Institute. Karolinska Institutet, Sweden.
    Mood impairment is stronger in young than in older adults after sleep deprivation2019In: Journal of Sleep Research, ISSN 0962-1105, E-ISSN 1365-2869, Vol. 28, no 4, article id e12801Article in journal (Refereed)
    Abstract [en]

    Sleep deprivation commonly impairs affective regulation and causes worse mood. However, the majority of previous research concerns young adults. Because susceptibility to sleep deprivation and emotion regulation change distinctively across adult age, we tested here the hypothesis that the effect of sleep deprivation on mood is stronger in young than in older adults. In an experimental design, young (18–30 years) and older adults (60–72 years) participated in either a sleep control (young, n = 63; older, n = 47) or a total sleep deprivation condition (young, n = 61; older, n = 47). Sleepiness, mood and common symptoms of sleep deprivation were measured using established questionnaires and ratings. Sleep‐deprived participants felt more sleepy, stressed and cold, and reported lower vigour and positive affect, regardless of age. All the other outcome measures (negative affect, depression, confusion, tension, anger, fatigue, total mood disturbance, hunger, cognitive attenuation, irritability) showed a weaker response to sleep deprivation in the older group, as indicated by age*sleep deprivation interactions (ps < 0.05). The results show that older adults are emotionally less affected by sleep deprivation than young adults. This tolerance was mainly related to an attenuated increase in negative mood. This could possibly be related to the well‐known positivity effect, which suggests that older adults prioritize regulating their emotions to optimize well‐being. The results also highlight that caution is warranted when generalizing results from sleep deprivation studies across the adult lifespan.

  • 99.
    Schwarz, Johanna F. A.
    et al.
    Stockholm University, Faculty of Social Sciences, Stress Research Institute.
    Ingre, Michael
    Stockholm University, Faculty of Social Sciences, Stress Research Institute.
    Fors, Carina
    Anund, Anna
    Kecklund, Göran
    Stockholm University, Faculty of Social Sciences, Stress Research Institute.
    Taillard, Jacques
    Phillip, Pierre
    Åkerstedt, Torbjörn
    Stockholm University, Faculty of Social Sciences, Stress Research Institute.
    In-car countermeasures open window and music revisited on the real road: popular but hardly effective against driver sleepiness2012In: Journal of Sleep Research, ISSN 0962-1105, E-ISSN 1365-2869, Vol. 21, no 5, p. 595-599Article in journal (Refereed)
    Abstract [en]

    This study investigated the effects of two very commonly used countermeasures against driver sleepiness, opening the window and listening to music, on subjective and physiological sleepiness measures during real road driving. In total, 24 individuals participated in the study. Sixteen participants received intermittent 10-min intervals of: (i) open window (2 cm opened); and (ii) listening to music, during both day and night driving on an open motorway. Both subjective sleepiness and physiological sleepiness (blink duration) was estimated to be significantly reduced when subjects listened to music, but the effect was only minor compared with the pronounced effects of night driving and driving duration. Open window had no attenuating effect on either sleepiness measure. No significant long-term effects beyond the actual countermeasure application intervals occurred, as shown by comparison to the control group (n = 8). Thus, despite their popularity, opening the window and listening to music cannot be recommended as sole countermeasures against driver sleepiness.

  • 100.
    Schwarz, Johanna F A
    et al.
    Stockholm University, Faculty of Social Sciences, Stress Research Institute.
    Lindberg, E
    Gruber, G
    Fischer, Håkan
    Theorell-Hagloew, J
    Åkerstedt, Torbjörn
    Stockholm University, Faculty of Social Sciences, Stress Research Institute.
    Effect of age on the macro- and microstructure of sleep in women2014In: Journal of sleep research, Special issue: abstracts of the 22nd Congress of the European Sleep Research Society, 16–20 September 2014, Tallinn, Estonia, Chichester: Wiley-Blackwell, 2014, p. 149-Conference paper (Other academic)
1234 51 - 100 of 167
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf