Insulin action after resistive training in insulin resistant older men and women.
OBJECTIVE
To determine the effects of resistive training (RT) on insulin action and assess the determinants of the changes in insulin action.


METHODS
Longitudinal study.


METHODS
Outpatient setting.


METHODS
Eighteen older men and older postmenopausal women (65-74 years) with normal (6 men and 5 women) or impaired glucose tolerance (4 men and 3 women).


METHODS
Six months of progressive whole-body RT.


METHODS
Upper and lower body strength was assessed by the one repetition maximum test. Total body fat and fat-free mass (FFM) were determined by dual-energy x-ray absorptiometry before and after 6 months of RT. Insulin sensitivity was estimated from the relationship of glucose utilization (M) to the concentration of insulin (I) during the last 30 minutes of 3-hour hyperinsulinemic-euglycenic clamps (240 pmol x min(-2) x min(-1)) (M/I) before and after RT.


RESULTS
RT significantly improved upper- and lower-body muscular strength (P < .005). FFM increased after RT in the entire group (P < .01) with no significant change in body fat. Although the change in M was larger in men (13%) than women (3%), the difference was not significant. The change in M was a function of initial M (r = -0.53, P < .05). There was a trend (0.060+/-0.006 vs 0.066+/-0.006 micromol x kg(-1) x min(-1)/pmol/l, n = 18) for M/I to increase after RT in the combined group of men and women (P = .06). There were no significant relationships between changes in M or M/I with changes in body composition or strength.


CONCLUSIONS
A 6-month RT program tends to improve insulin action in insulin-resistant older adults. These results suggest that RT may be useful in ameliorating insulin resistance that often occurs with physical inactivity, obesity, and loss of muscular strength in older insulin resistant men and women.
Ryan
A S
AS
Department of Medicine, University of Maryland School of Medicine, Baltimore VA Medical Center, MD, USA.
Hurlbut
D E
DE
Lott
M E
ME
Ivey
F M
FM
Fleg
J
J
Hurley
B F
BF
Goldberg
A P
AP
D000368:Aged; D000375:Aging / Q000502:physiology*; D000704:Analysis of Variance; D001786:Blood Glucose / Q000378:metabolism*; D002151:Calorimetry; D015444:Exercise / Q000502:physiology*; D005260:Female; D005951:Glucose Tolerance Test; D006801:Humans; D007328:Insulin / Q000378:metabolism*; D007333:Insulin Resistance / Q000502:physiology*; D008137:Longitudinal Studies; D008297:Male; D011336:Probability; D012680:Sensitivity and Specificity; D013997:Time Factors
D001786:Blood Glucose; D007328:Insulin