Does holiday hypoglycaemia exist?

Background. To determine whether an excessive, prolonged and, above all, un usual physical exertion could be associated with episodes of mild hypoglyca emia in non-insulin-dependent diabetes mellitus (NIDDM) patients treated wi th glibenclamide. Methods. Experimental design: 11 months of observation with retrospective a nalysis of patient personal diaries to determine the hypoglycaemic risk. Se tting: Diabetic Unit - Department of Medicine and Aging - Chieti University School of Medicine. Patients: We enrolled 340 NIDDM outpatients adjusted f or sex, age, body mass index, alcohol intake and oral treatment regimen wit h glibenclamide. Patients were tested monthly for circadian blood glucose p rofiles and glycosylated hemoglobin. Mild hypoglycaemia was defined on the basis of blood glucose values <2.8 mmol/l associated with mild autonomic sy mptoms, without requiring external assistance. Each diabetic patient filled a personal diary indicating the therapy regimen and the characteristics of eventual hypoglycaemic episodes occurring during the observation period. Results. 21.8% of NIDDM patients experienced one or two episodes of mild hy poglycaemia during the observation period. The analysis of the patients' di aries showed that 60% of the hypoglycaemic episodes was associated with exc essive, prolonged and unexpected physical exertions. Within this group, abo ut 70% of the episodes occurred during a holiday ("holiday hypoglycaemia"). After analyzing the socio-demographic and clinical characteristics of the diabetic patients reporting hypoglycaemic events, we found a higher risk fo r "holiday hypoglycaemia" in patients with a lower educational level, with a sedentary occupation or among the ex-farmers. Conclusions. As resulted in the present study, unexpected physical exertion s may represent a relevant cause of mild hypoglycaemia in diabetic patients receiving oral antidiabetic therapy. However, this hypoglycaemic cause may have been underestimated in the literature. Educational programs conducted by general practitioners or diabetologists could be useful for the patient s in reducing the number of mild hypoglycaemic episodes.