title: Glucose ingestion and substrate utilization during exercise in boys with IDDM.
abstract: This study was intended to compare exogenous [(13)C]glucose (Glu(exo)) oxidation in boys with insulin-dependent diabetes mellitus (IDDM) and healthy boys of similar age, weight, and maximal O(2) uptake. In a control trial with water intake (CT) and in a (13)C-enriched glucose trial (GT), subjects cycled for 60 min (58.8 +/- 0.9% maximal O(2) uptake) while the utilization of total glucose, total fat, and Glu(exo) 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, Glu(exo) 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, Glu(exo) is impaired in exercising boys with IDDM, even when plasma insulin levels are elevated.
authors.affiliation: Children's Exercise and Nutrition Centre, McMaster University, Hamilton, Ontario, Canada L8N 3Z5.
authors.forename: M C
authors.initials: MC
authors.lastname: Riddell
authors.forename: O
authors.initials: O
authors.lastname: Bar-Or
authors.forename: M
authors.initials: M
authors.lastname: Hollidge-Horvat
authors.forename: H P
authors.initials: HP
authors.lastname: Schwarcz
authors.forename: G J
authors.initials: GJ
authors.lastname: Heigenhauser
mesh_terms: D000293:Adolescent; D000328:Adult; D001786:Blood Glucose / Q000378:metabolism; D002247:Carbon Isotopes; D003922:Diabetes Mellitus, Type 1 / Q000378:metabolism / Q000503:physiopathology*; D015444:Exercise / Q000502:physiology*; D005947:Glucose / Q000378:metabolism*; D006019:Glycolysis; D006339:Heart Rate; D006801:Humans; D007328:Insulin / Q000097:blood; D008297:Male; D010101:Oxygen Consumption; D005082:Physical Exertion / Q000502:physiology*; D012016:Reference Values
chemical_list: D001786:Blood Glucose; D002247:Carbon Isotopes; D007328:Insulin; D005947:Glucose