Conclusions and Relevance This systematic review and meta- analysis did not show a significant beneficial or detrimental association of HT with muscle mass .
Importance Hormone therapy ( HT ) has been suggested for protection against age-related muscle weakness in women .
However , the potential for HT-associated health risks necessitates a better underst and ing of the direction and magnitude of the association between HT and health outcomes , such as lean body mass ( LBM ) .
Objective To determine whether HT was associated with reduced LBM loss compared with not receiving HT  among postmenopausal women aged 50 years and older .
Effects of HRT and exercise training on insulin action, glucose tolerance, and body composition in older women.
The independent and combined effects of exercise training and hormone replacement therapy ( HRT ) on body composition , fat distribution , glucose tolerance , and insulin action were studied in postmenopausal women , aged 68 + /- 5 yr , assigned to control ( n = 19 ) , exercise ( n = 18 ) , HRT ( n = 15 ) , and exercise + HRT ( n = 16 ) groups . The exercise consisted of 2 mo of flexibility exercises followed by 9 mo of endurance exercise . HRT was conjugated estrogens 0.625 mg/day and trimonthly medroxyprogesterone acetate 5 mg/day for 13 days . Total and regional body composition were measured by dual-energy X-ray absorptiometry . Serum glucose and insulin responses were measured during a 2-h oral glucose tolerance test . There were significant main effects of exercise on reductions in total and regional ( trunk , arms , legs ) fat mass , increase in leg fat-free mass , and improvements in glucose tolerance and insulin action . There were significant main effects of HRT on the reduction of total fat mass ( HRT , -3.0 + /- 4.0 kg ; no HRT , -1.3 + /- 2.6 kg ) , with a strong trend for reductions in trunk and leg fat mass ( both P = 0.07 ) . There was also a significant improvement in insulin action in response to HRT . These results suggest that there are independent and additive effects of exercise training and HRT on the reduction in fat mass and improvement in insulin action in postmenopausal women ; the effect of HRT on insulin action may be mediated , in part , through changes in central adiposity
Conclusions and Relevance This systematic review and meta- analysis did not show a significant beneficial or detrimental association of HT with muscle mass .
Importance Hormone therapy ( HT ) has been suggested for protection against age-related muscle weakness in women .
However , the potential for HT-associated health risks necessitates a better underst and ing of the direction and magnitude of the association between HT and health outcomes , such as lean body mass ( LBM ) .
Objective To determine whether HT was associated with reduced LBM loss compared with not receiving HT  among postmenopausal women aged 50 years and older .