Use of an alpha-glucosidase inhibitor to maintain glucose homoeostasis during postprandial exercise in intensively treated Type 1 diabetic subjects

Aim We evaluated the effects of an alpha -glucosidase inhibitor, acarbose, on glucose homoeostasis during postprandial exercise in Type 1 diabetic sub jects. Methods Seven Type 1 diabetic subjects with good glycaemic control on ultra lente-regular insulin were randomized in a single blind cross-over study to acarbose 100 mg or placebo taken with a mixed meal (600 kcal, 75 g carbohy drates), followed 90 min later by 30 min of exercise at 50% maximum aerobic capacity. Glucose turnover was measured by tracer (d-[6,6,H-2(2)]glucose) methodology, and intestinal glucose absorption was quantified using carbohy drate polymers labelled with [C-13]glucose. Results Acarbose resulted in a significant decrease in the postprandial gly caemic rise (mean +/- SEM 2.9 +/- 0.6 vs. 5.0 +/- 0.7 mmol/l; P < 0.005) an d in the glycaemic nadir during exercise (- 0.8 +/- 0.6 vs. 0.9 +/- 1.3 mmo l/l below baseline; P < 0.05). Total glucose appearance increased similarly under the two treatments during the postprandial (27.0 vs. 27.9 mu mol per kg per min) and exercise (33.9 vs. 33.5 mu mol per kg per min) periods. Me an glucose absorption was significantly delayed by acarbose (7.8 vs. 10.2 m u mol per kg per min; P < 0.02), but was compensated by the lack of postpra ndial suppression of hepatic glucose production (106% of basal hepatic gluc ose production vs. 81%; P < 0.006). Episodes of hypoglycaemia were no diffe rent (three vs. six). Conclusion These results indicate that, in Type 1 diabetic subjects, acarbo se results in a better glycaemic profile during postprandial exercise and s uggest that it could lead to a lower risk of exercise-induced hypoglycaemia due to delayed glucose absorption and less suppression of hepatic glucose production.