We found a match
Your institution may have rights to this item. Sign in to continue.
- Title
Aerobic Exercise Plus Weight Loss Improves Insulin Sensitivity and Increases Skeletal Muscle Glycogen Synthase Activity in Older Men.
- Authors
Ryan, Alice S.; Katzel, Leslie I.; Prior, Steven J.; McLenithan, John C.; Goldberg, Andrew P.; Ortmeyer, Heidi K.
- Abstract
The purpose of this study was to determine the effects of 6-month aerobic exercise training + weight loss (AEX + WL) on basal and insulin activation of glycogen synthase, basal citrate synthase activity, and Akt and AS160 phosphorylation in older, overweight/obese insulin-resistant men (n = 14; 63 ± 2 years; body mass index, 32 ± kg/m2). Muscle samples of the vastus lateralis were collected before and during a 3-hour 80 mU/m2/min hyperinsulinemic-euglycemic clamp. AEX + WL increased VO2max by 11% (p < .05) and decreased body weight (−9%, p < .001). AEX + WL increased basal citrate synthase activity by 46% (p < .01) and insulin activation of independent (2.9-fold) and fractional (2.3-fold) activities (both p < .001) of glycogen synthase. AEX + WL had no effect on phosphorylation of Akt or AS160. Glucose utilization (M) improved 25% (p < .01), and the change tended to be related to the increase in insulin activation of glycogen synthase fractional activity (r = .50, p = .08) following AEX + WL. In summary, AEX + WL has a robust effect on insulin activation of skeletal muscle glycogen synthase activity that likely contributes to improved glucose utilization in older insulin-resistant men.
- Subjects
OBESITY; HEALTH of older men; PHYSIOLOGICAL aspects of aerobic exercises; WEIGHT loss; EXERCISE physiology; INSULIN resistance; BODY weight; GLYCOGEN synthases; PHYSIOLOGY
- Publication
Journals of Gerontology Series A: Biological Sciences & Medical Sciences, 2014, Vol 69, Issue 7, p790
- ISSN
1079-5006
- Publication type
Article
- DOI
10.1093/gerona/glt200