High Risk Periods for Hypoglycemia

Seasonal and weekly variations in hypoglycemia may affect patients with T1DM more than those with T2DM, according to a study published in the Journal of Diabetes Complications.  

Specifically, the study found that those with T1DM experience significantly more episodes of severe hypoglycemia during warmer months and on weekends (especially Saturday), than those with T2DM.

“[F]or the risk of restrictively defined SH [severe hypoglycemia], time factors appear to contribute more substantially in younger, physically more active individuals with fewer co-morbidities and T1DM than in prevailing geriatric subjects with T2DM,” wrote first author Andreas Holstein, MD, of the Lippe-Detmold Hospital (Detmold, Germany), and colleagues.

The study is the first to evaluate weekday variability in hypoglycemia among diabetics in a real world setting, and one of only a handful to look at seasonal variations in hypoglycemia.

In the prospective observational study, researchers identified all people treated for episodes of severe hypoglycemia at the tertiary care Lippe-Detmold Hospital between 2007 and 2014. The Lippe-Detmold area of Germany is an urban-rural region in East Westphalia, and has about 200,000 inhabitants.  Researchers defined severe hypoglycemia as a symptomatic episode requiring intravenous glucose or glucagon, and confirmed by blood glucose <2.8 mmol/L (<50 mg/dL).

Key Results:

• 1080 episodes of severe hypoglycemia occurred in 747 patients during the study: 37.5% in patients with T1DM, and 51.9% in T2DM

• T1DM:

♦ Mean age 48.1, 89.3% lived independently, Charlson comorbidity index 4.0

♦ 30.4% of severe hypoglycemia happened between 12:00 and 18:00 (P<0.001)

♦ Significantly higher rates of severe hypoglycemia on weekends, especially Saturday, compared to weekdays (P=0.004)

♦ Significantly higher rates of severe hypoglycemia in spring (31.2%) and summer (26.7%) compared to autumn (20.3%) and winter (21.8%) (P<0.05)

♦ HbA1c and insulin doses did not vary by season (P>0.05 for both)

• T2DM:

♦ Mean age 77.3, 38.6% lived in nursing homes or with home nursing services, Charlson comorbidity index 8.8

♦ 35% of severe hypoglycemia occurred between 12:00 and 18:00 (P<0.001)

♦ No significant differences in seasonal distribution of severe hypoglycemia: winter 26.1%, spring 24.5%, summer 23.2%, fall 26.3%

♦ No peak incidence over the weekend

The authors suggested that short-term changes related to leisure-time activities-like increased exercise or alcohol intake-could contribute to these findings. They also highlighted a nonsignificant trend toward younger age and fewer comorbidities among those who experienced severe hypoglycemia on weekends compared to during the week. 

In contrast, the population with T2DM were older, had more comorbidities, and had a greater percentage of institutionalized individuals than those with T1DM. So exercise and alcohol consumption may have been more restricted in this group. Also, individuals in nursing homes may have had more steady daily caloric intake, making them less susceptible to weekday variations in hypoglycemia.

“For the risk of SH, temporal factors appear to contribute more substantially in younger, physically more active individuals with fewer co-morbidities and T1DM than in prevailingly geriatric subjects with T2DM,” the authors concluded, “…Intensification of diabetes care and education with better adjustment of insulin doses in these susceptible periods could be an appropriate approach to prevent SH.”

Take-home Points

• Single center study in Germany found significantly increased rates of severe hypoglycemia in warmer months and on weekdays-specially Saturdays-in patients with T1DM compared to those with T2DM.

• Short-term changes in behavior related to leisure-time activities, like increased exercise and alcohol consumption, might explain these results.

• Intensified diabetes care and education, and improved adjustment of insulin doses during these time periods may help prevent severe hypoglycemia.

Reference: Holstein A, et al. Accumulation of severe hypoglycemia at weekends and in warm seasons in patients with type 1 diabetes but not with type 2 diabetes. J Diabetes Complications. 2016 Jun 3.