AJP - Endocrinology and Metabolism, Vol 260, Issue 1 E14-E20, Copyright © 1991 by American Physiological Society
Effect of training on response to a glucose load adjusted for daily carbohydrate intake
F. Dela, K. J. Mikines, M. Von Linstow and H. Galbo
Department of Medical Physiology B, Panum Institute, Copenhagen, Denmark.
From responses to identical absolute glucose loads in trained (T) and
untrained (UT) subjects, it has been inferred that training promotes health
by reducing glucose levels and insulin secretion. To mimic daily living
conditions, we studied responses to oral glucose loads making up identical
fractions of daily carbohydrate intake (i.e., same relative glucose load)
in seven T and eight UT males [maximal O2 uptake (VO2max) 76 +/- 2 vs. 48
+/- 1 (SE) ml.min-1.kg-1; age 24 +/- 1 vs. 25 +/- 1 yr]. Daily energy
intake was higher in T than in UT subjects (18,607 +/- 835 vs. 12,493 +/-
720 kJ/day, P less than 0.05), reflecting a 2.3 times higher carbohydrate
intake (678 +/- 34 vs. 294 +/- 18 g/day, P less than 0.05). After 1 g/kg
body wt glucose, C-peptide and insulin responses were lower in T than in UT
subjects (P less than 0.05). However, after identical relative glucose
loads [high: 2.3 +/- 0.2 (T) vs. 1 (UT) g/kg; low: 1 (T) vs. 0.4 +/- 0.03
(UT) g/kg], glucose [incremental areas 300 +/- 56 (T) vs. 304 +/- 35 (UT)
mM.180 min and 148 +/- 30 (T) vs. 124 +/- 22 (UT)] and C-peptide [181 +/-
18 (T) vs. 171 +/- 27 (UT) nM.180 min, and 100 +/- 13 (T) vs. 71 +/- 12
(UT)] responses did not differ between groups, while insulin responses were
lower in T [at low relative load 15 +/- 4 (T) vs. 20 +/- 2 (UT) nM.180 min,
P less than 0.05].(ABSTRACT TRUNCATED AT 250 WORDS)
