Accommodating planned exercise in type I diabetic patients on intensive treatment

To achieve optimal metabolic control in type I diabetic patients treated with continuous subcutaneous insulin infusion (CSII) and multiple subcutaneous injections of insulin (MSI) appropriate adjustments of the insulin prescription should be made for exercise, which is a normal component of everyday life. The present study describes the responses of seven type I diabetic adolescents treated with CSII and six patients treated with MSI to specific insulin dose changes in anticipation of postprandial exercise. The effect of 45 min of cycle ergometer exercise at 55% VO2 on glucose regulation was studied 2 h after morning insulin and a breakfast meal. To quantify the potential benefit of modifying the insulin dose before exercise, the subjects were studied on five different days in a random order: resting control day, postprandial exercise preceded by the usual dose of insulin, postprandial exercise preceded by one-half of the usual dose of insulin, postprandial exercise preceded by two-thirds of the usual dose of insulin, and postprandial exercise without the usual dose of insulin. In all cases insulin was injected or infused subcutaneously in the anterior abdominal wall. When exercise was performed without changing the usual insulin dose, there was a significant fall in glycemia in both groups, with the nadir occurring after 45 min. In the CSII group, the +/- SEM plasma glucose was 57 +/- 5 mg/dl (P less than 0.05 versus rest) with hypoglycemia occurring in four patients. In the MSI group, the mean +/- SEM plasma glucose fell to 65 +/- 10 mg/dl (P less than 0.05 versus rest) and hypoglycemia occurred in three patients.(ABSTRACT TRUNCATED AT 250 WORDS)