Postmenopausal HRT and tibolone in relation to muscle strength and body composition

Objectives: Sarcopenia, the loss of muscle mass with age, has a great impact on physical function, and especially in postmenopausal women, who experience a greater decline in muscle strength than do men of similar age. Conventional hormone replacement therapy (HRT) may diminish this loss of muscle strength and may even increase muscle strength. However, HRT is not currently promoted for this indication because of its negative side effects, which is why tibolone, a synthetic steroid with oestrogenic, progestogenic, and androgenic activity, may be an alternative option. The aim of this article was to review data on the effect of HRT and tibolone on muscle strength and body composition in postmenopausal women. Methods: Medline, Pubmed, Embase, and Sumsearch were searched for articles on the effect of HRT and tibolone on muscle strength and body composition, using the Mesh terms hormone replacement therapy and clinical trial combined with muscle strength or body composition. Tibolone was added as search term with clinical trial and muscle strength or body composition. Results: Three of five randomized controlled trials reported a significant positive effect of HRT on muscle strength but not on body composition. Tibolone significantly increased handgrip strength and isometric knee extension strength in one randomized placebo-controlled, double-blind trial and increased mean knee extensor strength in one cross-sectional study. Tibolone also increased the lean body mass and decreased the accumulation of body fat. Conclusions: HRT and tibolone increase muscle strength. Unlike HRT, tibolone also increases lean body mass and significantly reduces the total body fat content. Further research is recommended to determine whether tibolone is a safe treatment for sarcopenia. (c) 2007 Elsevier Ireland Ltd. All rights reserved.