Exercise Training with Hormone Replacement Therapy Has No Synergistic Effect on the Improvement of Lean and Fat Mass in Postmenopausal Women: A Meta-analysis of Randomized Controlled Trials

Abstract

Objectives: Postmenopausal women possess lower skeletal muscle mass, associated with a higher prevalence of metabolic syndrome, compared to premenopausal women. Maintaining skeletal muscle mass appears to be imperative to protect against the menopause-associated metabolic syndrome in women. The present study conducted a meta-analysis of randomized controlled trials to investigate the effectiveness of exercise training with or without hormone replacement therapy (HRT) on lean and fat mass in postmenopausal women. Study design: Four studies qualified for the meta-analysis, and the effect sizes were calculated by comparing changes in lean and fat mass between pre- and post-treatment. Moderator variable analysis examined potential different effects among four sub-groups based on specific interventions: (a) HRT+NEX (no-exercise), (b) HRT+EX (exercise), (c) NHRT (non-HRT)+NEX, and (d) NHRT+EX. Results: Random effects model meta-analysis revealed no significant overall effects of exercise training with or without HRT on fat mass, whereas the analysis found a significant positive overall effects on lean mass (Hedges’g = 0.22, P = 0.039). Although our moderator variable analyses failed to show significant effect sizes for all the sub-groups, the two sub-groups with exercise training showed a trend of positive effects on lean mass (i.e., HRT+EX: P = 0.08 and NHRT+EX: P = 0.12). Conclusion: Our meta-analytic findings suggested that exercise training, but not HRT, may be effective for increasing lean mass in postmenopausal women. Future studies should include more evidence to validate the potential combining effect of exercise training and HRT.