Isomaltulose improves glycaemia and maintains run performance in Type 1 Diabetes

Purpose Individuals with type 1 diabetes (T1DM) are encouraged to reduce rapid-acting insulin and consume carbohydrates to prevent hypoglycemia during or after exercise. However, research comparing the metabolic and performance effects of different carbohydrates is limited. This study compared the alterations in metabolism and fuel oxidation in response to performance running following pre-exercise ingestion of isomaltulose or dextrose in T1DM. Methods Following preliminary testing, on two occasions seven T1DM individuals consumed 0.6 g.kg-1 body mass of either dextrose (DEX; GI 96), or isomaltulose (ISO; GI 32), two hours before a discontinuous, incremental run to 80 %VO2peak on a motorised treadmill followed by a 10 minute all-out performance test on a non-motorised treadmill. Blood glucose (BG), acid-base and cardio-respiratory parameters were measured for 2 hours before, during and after both run tests. Data (mean +/- SEM) were analysed using repeated-measures ANOVA. Results Pre-exercise BGAUC was lower under ISO in comparison with DEX (ISO +4.0 +/- 0.3 vs. DEX +7.0 +/- 0.6 mmol.l-1.hour-1, P