Influence of and Optimal Insulin Therapy for a Low–Glycemic Index Meal in Children With Type 1 Diabetes Receiving Intensive Insulin Therapy

Abstract

OBJECTIVE—The purpose of this study was to quantify the effects of glycemic index on postprandial glucose excursion (PPGE) in children with type 1 diabetes receiving multiple daily injections and to determine optimal insulin therapy for a low–glycemic index meal. RESEARCH DESIGN AND METHODS—Twenty subjects consumed test breakfasts with equal macronutrient contents on 4 consecutive days; high–and low–glycemic index meals (glycemic index 84 vs. 48) were consumed with preprandial ultra-short-acting insulin, and the low–glycemic index meal was also consumed with preprandial regular insulin and postprandial ultra-short-acting insulin. Each child's insulin dose was standardized. Continuous glucose monitoring was used. RESULTS—The PPGE was significantly lower for the low–glycemic index meal compared with the high–glycemic index meal at 30–180 min (P < 0.02) when preprandial ultra-short-acting insulin was administered. The maximum difference occurred at 60 min (4.2 mmol/l, P < 0.0001). Regular insulin produced a 1.1 mmol/l higher PPGE at 30 min compared with ultra-short-acting insulin (P = 0.015) when the low–glycemic index meal was consumed. Postprandial ultra-short-acting insulin produced a higher PPGE at 30 and 60 min compared with preprandial administration when the low–glycemic index meal was consumed. The maximum difference was 2.5 mmol/l at 60 min (P < 0.0001). CONCLUSIONS—Low–glycemic index meals produce a lower PPGE than high–glycemic index meals. Preprandial ultra-short-acting insulin is the optimal therapy for a low–glycemic index meal.