The aim of this study was to investigate fear of hypoglycemia (FoH) longitudinally in adult patients with type 1 diabetes. Specifically, we investigated two subgroups of patients who over four years either showed a significantly higher or significantly lower level of FoH in order to identify factors associated with changes in FoH.
The Swedish version of the Hypoglycemia Fear Survey (HFS) along with a questionnaire to assess hypoglycemia history (mild, moderate, nocturnal and severe hypoglycaemia (SH), unawareness, and daytime/nocturnal self-monitoring of blood glucose (SMBG)) were sent by mail to 764 patients in 2010. The responders in 2010 (n=469) received another set of the same two questionnaires in 2014. A1c, insulin regimen, weight and creatinine from 2010 and 2014 were obtained from medical records. Those with an absolute difference in HFS scores ≥ 75th percentile were included in the subgroup analyses. Statistical analyses included one-sample t-tests and chi-square.
The absolute difference in the HFS total score (n=359) between 2010 and 2014 was m=±7.6, SD ±6 (range -29 - +35). In the subgroup with increased FoH 2014 (n=45), more patients reported unawareness (76% vs 58%, Χ2= 5.05, p= 0.025) and a higher frequency of moderate hypoglycemia (52% v s 38%, Χ2= 3.93, p= 0.047) compared to 2010. In the group with decreased FoH (n=43), fewer patients reported going to the emergency department due to hypoglycemia in 2014 compared to 2010 (2% vs 14%, Χ2= 4.84, p= 0.028). There were no differences in the remaining hypoglycemia history variables or medical variables between 2010 and 2014. Between group analyzes show that in the decreased FoH group more patients have a high frequency of daily SMBG compared to the increased FoH group in 2010 (35% vs 17%, Χ2= 12.23, p= 0.00) and in 2014 (33% vs 13%, Χ2= 13.75, p= 0.00). In the increased FoH group more patients report a high level of mild (67% vs 49%,Χ2= 6.4, p= 0.011) and moderate (52% vs 23%,Χ2= 14.00, p= 0.00) hypoglycemic episodes as well as unawareness (76% vs 54%,Χ2= 11.37, p= 0.001) in 2014 compared with the decreased FoH group.
To our knowledge, this is the first longitudinal study of FoH in patients with type 1 diabetes. Our study shows that FoH is stable across time for most patients although a number of patients show increased or decreased levels of FoH. The patients whose level of FoH increased experienced a higher frequency of moderate hypoglycemic episodes and more hypoglycemic unawareness in 2014.
International Diabetes Federation, World Diabetes Congress, Vancouver, Canada, November 30th-December 4th, 2015.