A new table for prevention of hypoglycaemia during physical activity in type 1 diabetic patients

The ability to adjust both insulin and nutrition to allow safe participation in physical activity and high performance has recently been recognized as an important management strategy in these patients. In particular, the important role played by the patient in self-monitoring blood glucose during physical activity and then using these data to improve performance and decrease hypoglycaemias is now fully accepted. The primary objective of this study is to compare different therapeutic options in exercising Type 1 diabetic patients (n=67) with or without CHO compensation and/or with or without insulin dosage reduction in order to prevent hypoglycaemias during and after exercise.

Sixty-seven type 1 diabetic patients were aggregated into four treatment categories according to four strategies to prevent hypoglycaemia episodes, with or without carbohydrate compensation and/or with or without insulin dosage reduction. The protocol included 7 different disciplines and 9 subgroups according to 3 different durations (<20 min., 20-60 min., > 60 min.) and 3 intensity degrees (<60% of Maximal Heart Rate, 60-75% and > 75%).

Our study shows that by replacing adequately the carbohydrates during the practice of physical exercise it is possible to prevent almost all hypoglycaemia episodes, independently of the insulin dosage adjustments. Furthermore, the amount of extra-carbohydrates correlates well with the number of hypoglycaemia while the decrease in insulin dosage does not.

Adequate carbohydrate replacement during and after exercise seems to be the most important measure to prevent hypoglycaemia. However, the insulin dosage adjustment does not play such an important role. A decrease from 20 to 30% seems reasonable only for a long duration exercise (> 60 min.). Finally, a new user-friendly table for prevention of hypoglycaemia is proposed for physical activity of different intensity and duration.