Impact of exercise on overnight glycemic control in - Children with type 1 diabetes mellitus

Objective To examine the effect of exercise on overnight hypoglycemia in children with type 1 diabetes mellitus (T1DM). Study design At 5 clinical sites, 50 subjects with T1DM (age 11 to 17 years) were studied in a clinical research center on 2 separate days. One day included an afternoon exercise session on a treadmill. On both days, frequently sampled blood glucose levels were measured at the DirecNet central laboratory. Insulin doses were similar on both days. Results During exercise, plasma glucose levels fell in almost all subjects; 11 (22%) developed hypoglycemia. Mean glucose Hypoglycemia level from 10 PM to 6 AM was lower on the exercise day than on the sedentary day (131 vs 154 mg/dL; P =.003). developed overnight more often on the exercise nights than on the sedentary nights (P =.009), occurring on the exercise night only in 13 (26%), on the sedentary night only in 3 (6%), on both nights in 11 (22%), and on neither night in 23 (46%). Hypoglycamia was unusual on the sedentry night if the pre-bedtime snack glucose level was > 130 mg/dL. Conclusions These findings indicate that overnight hypoglycemia is common in children with T1DM and support the importance of modifying diabetes management after afternoon exercise to reduce the risk of hypoglycemia.