TY - JOUR
T1 - Impact of hormone replacement therapy on exercise training-induced improvements in insulin action in sedentary overweight adults
AU - Huffman, Kim M.
AU - Slentz, Cris A.
AU - Johnson, Johanna L.
AU - Samsa, Gregory P.
AU - Duscha, Brian D.
AU - Tanner, Charles J.
AU - Annex, Brian H.
AU - Houmard, Joseph A.
AU - Kraus, William E.
N1 - Funding Information:
We thank the rest of the STRRIDE research team at East Carolina University and Duke University. We appreciate thoughtful input from Drs Svati Shah and Andrew Goldberg. This work was supported by the National Heart, Lung, and Blood Institute (National Institutes of Health) R01HL-57354 (Kraus, PI) and National Institute on Aging (National Institutes of Health) P30 AGO28716-01 (Cohen, PI) and AG028930-01 (Muoio, PI).
PY - 2008/7
Y1 - 2008/7
N2 - Exercise training (ET) and hormone replacement therapy (HRT) are both recognized influences on insulin action, but the influence of HRT on responses to ET has not been examined. To determine if HRT use provided additive benefits for the response of insulin action to ET, we evaluated the impact of HRT use on changes in insulin during the course of a randomized, controlled, aerobic ET intervention. Subjects at baseline were sedentary, dyslipidemic, and overweight. These individuals were randomized to 6 months of one of 3 aerobic ET interventions or continued physical inactivity. In 206 subjects, an insulin sensitivity index (SI) was obtained with a frequently sampled intravenous glucose tolerance test pre- and post-ET. Baseline and postintervention fitness, regional adiposity, general adiposity, skeletal muscle biochemistry and histology, and serum lipoproteins were measured as other putative mediators influencing insulin action. Two-way analyses of variance were used to determine if sex or HRT use influenced responses to exercise training. Linear modeling was used to determine if predictors for response in SI differed by sex or HRT use. Women who used HRT (HRT+) demonstrated significantly greater improvements in SI with ET than women not using HRT (HRT-). In those HRT+ women, plasma triglyceride change best correlated with change in SI. For HRT- women, capillary density change and, for men, subcutaneous adiposity change best correlated with change in SI. In summary, in an ET intervention, HRT use appears to be associated with more robust responses in insulin action. Furthermore, relationships between ET-induced changes in insulin action and potential mediators of change in insulin action are different for men, and for women on or off HRT. These findings have implications for the relative utility of ET for improving insulin action in middle-aged men and women, particularly in the setting of differences in HRT use.
AB - Exercise training (ET) and hormone replacement therapy (HRT) are both recognized influences on insulin action, but the influence of HRT on responses to ET has not been examined. To determine if HRT use provided additive benefits for the response of insulin action to ET, we evaluated the impact of HRT use on changes in insulin during the course of a randomized, controlled, aerobic ET intervention. Subjects at baseline were sedentary, dyslipidemic, and overweight. These individuals were randomized to 6 months of one of 3 aerobic ET interventions or continued physical inactivity. In 206 subjects, an insulin sensitivity index (SI) was obtained with a frequently sampled intravenous glucose tolerance test pre- and post-ET. Baseline and postintervention fitness, regional adiposity, general adiposity, skeletal muscle biochemistry and histology, and serum lipoproteins were measured as other putative mediators influencing insulin action. Two-way analyses of variance were used to determine if sex or HRT use influenced responses to exercise training. Linear modeling was used to determine if predictors for response in SI differed by sex or HRT use. Women who used HRT (HRT+) demonstrated significantly greater improvements in SI with ET than women not using HRT (HRT-). In those HRT+ women, plasma triglyceride change best correlated with change in SI. For HRT- women, capillary density change and, for men, subcutaneous adiposity change best correlated with change in SI. In summary, in an ET intervention, HRT use appears to be associated with more robust responses in insulin action. Furthermore, relationships between ET-induced changes in insulin action and potential mediators of change in insulin action are different for men, and for women on or off HRT. These findings have implications for the relative utility of ET for improving insulin action in middle-aged men and women, particularly in the setting of differences in HRT use.
UR - http://www.scopus.com/inward/record.url?scp=44949134224&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=44949134224&partnerID=8YFLogxK
U2 - 10.1016/j.metabol.2008.01.034
DO - 10.1016/j.metabol.2008.01.034
M3 - Article
C2 - 18555828
AN - SCOPUS:44949134224
VL - 57
SP - 888
EP - 895
JO - Metabolism: Clinical and Experimental
JF - Metabolism: Clinical and Experimental
SN - 0026-0495
IS - 7
ER -