Seasonal Variation in Severe Glucose-lowering Drug-induced Hypoglycemia in Patients with Type 2 Diabetes

Abstract

Objective Glucose-lowering drug-induced hypoglycemia is a serious complication and there have been a few reports of seasonal variations in hypoglycemia in patients with type 2 diabetes. The aim of the present study was to examine the association between severe drug-induced hypoglycemia and seasonal variations, and to elucidate the contributing factors. Methods This retrospective, single center clinical study, analyzed the cases of 125 patients who required emergency hospitalization for severe drug-induced hypoglycemia between January 1, 2001 and December 31, 2014. The period from November to April was defined as the cold season. Results Severe hypoglycemia occurred more often in the cold season than in the warm season. In the cold season, 62 of 9,981 (0.6%) emergency department visits involved patients who required hospitalization for drug-induced hypoglycemia. In contrast, in the warm season, 27 of 8,649 (0.3%) visits involved patients who required hospitalization for drug-induced hypoglycemia (p=0.002). The proportion of patients treated with sulfonylurea (SU) in the cold season was higher than that in the warm season. Even the use of low-dose SU caused hypoglycemia in the cold season. In the SU-treated group, the proportion of patients with white blood cell and/or C-reactive protein elevation was higher in the cold season than in the warm season (p=0.04). Conclusion Severe glucose-lowering drug-induced hypoglycemia occured more frequently in the cold season than in the warm season, and was associated with an inflammatory state in patients treated with SU.