Effect of resistance training with or without chromium picolinate supplementation on glucose metabolism in older men and women.
The effect of 12 weeks of resistance training (RT) with or without chromium picolinate (Cr-pic) supplementation on glucose tolerance was assessed in moderately overweight older men and women (age, 62 +/- 4 years; body mass index [BMI], 29.1 +/- 2.5 kg/m2). Seventeen men and 15 women were randomized to groups that consumed either 17.8 micromol chromium per day (924 microg Cr/d) as Cr-pic or a placebo (<0.1 microg Cr/d) while performing RT twice weekly. For all 32 subjects combined, fasting glucose increased but there were no changes in insulin or C-peptide concentrations after 12 weeks of RT. In response to an oral glucose challenge, the glucose and C-peptide areas under the curve (AUCs) were unchanged, whereas there was a 19% decrease in the insulin AUC (from 68 +/- 53 to 55 +/- 29 x 10(3) pmol/L/180 min, P = .045). The RT responses for the fasting concentration or AUC for glucose, insulin, or C-peptide were not influenced by Cr-pic. The decrease in the insulin AUC without any change in insulin secretion, as evidenced by a lack of change in the C-peptide AUC, suggests enhanced insulin clearance from the circulation with RT. Collectively, these data suggest that RT decreases the insulin response following an oral glucose challenge in older moderately overweight men and women without affecting glucose tolerance. The data also suggest that the decrease in circulating insulin may result from an increase in insulin clearance, not a decrease in insulin secretion. High-dose Cr-pic supplementation had no effect on any measure of glucose metabolism during RT.
Joseph
L J
LJ
Noll Physiological Research Center and Graduate Program in Physiology, The Pennsylvania State University, University Park, USA.
Farrell
P A
PA
Davey
S L
SL
Evans
W J
WJ
Campbell
W W
WW
D000368:Aged; D001786:Blood Glucose / Q000032:analysis; D002096:C-Peptide / Q000097:blood; D004311:Double-Blind Method; D005215:Fasting / Q000097:blood; D005260:Female; D005947:Glucose / Q000378:metabolism*; D006801:Humans; D007328:Insulin / Q000097:blood; D008297:Male; D008875:Middle Aged; D010806:Physical Education and Training; D010807:Physical Endurance / Q000502:physiology; D010848:Picolinic Acids / Q000494:pharmacology*; D014891:Weight Lifting / Q000502:physiology*
D001786:Blood Glucose; D002096:C-Peptide; D007328:Insulin; D010848:Picolinic Acids; D005947:Glucose; C030614:picolinic acid