Glucose ingestion and substrate utilization during exercise in boys with IDDM

This study was intended to compare exogenous [13C]glucose (Gluexo) oxidation in boys with insulin-dependent diabetes mellitus (IDDM) and healthy boys of similar age, weight, and maximal O2 uptake. In a control trial with water intake (CT) and in a 13C-enriched glucose trial (GT), subjects cycled for 60 min (58.8 ± 0.9% maximal O2 uptake) while the utilization of total glucose, total fat, and Gluexo was assessed. In CT, total glucose was 84.7 ± 9.2 vs. 91.3 ± 6.6 g/60 min (not significantly different) and total fat was 13.3 ± 2.2 vs. 11.1 ± 1.7 g/60 min (not significantly different) in IDDM vs. healthy boys, respectively. In GT, Gluexo was 10.4 ± 1.7 vs. 14.8 ± 1.1 g/60 min, corresponding to 9.0 ± 1.0 vs. 12.4 ± 0.5% of the total energy supply in IDDM and healthy boys, respectively ( P < 0.05). Endogenous glucose was spared in both groups by 12.6 ± 3.5% ( P < 0.05). Blood glucose and plasma insulin concentrations were two- to threefold higher in IDDM vs. healthy boys in both trials. In conclusion, Gluexo is impaired in exercising boys with IDDM, even when plasma insulin levels are elevated.

Glucose ingestion and substrate utilization during exercise in boys with IDDM Journal Articles