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 .
Muscular transcriptome in postmenopausal women with or without hormone replacement.
The loss of muscle mass and strength with aging is well characterized , but our knowledge of the molecular mechanisms underlying the development of sarcopenia remains incomplete . Although menopause is often accompanied with first signs of age-associated changes in muscle structure and function , the effects of hormone replacement therapy ( HRT ) or menopause-related decline in estrogen production in the muscles of postmenopausal women is not well understood . Furthermore the knowledge of the global transcriptional changes that take place in skeletal muscle in relation to estrogen status has thus far been completely lacking . We used a r and omized double-blinded study design together with an explorative microarray experiment to characterize possible effects of continuous , combined HRT and estrogen deprivation on the skeletal muscle of fifteen women . Here , we report the differential response of both Gene Ontology-annotated biological processes and some individual genes responding differentially to the use or non-use of HRT . Our results revealed transcription level changes in , for example , muscle protein and energy metabolism . In particular , the ubiquitine-proteosome system was found to be effected at several levels . HRT seemed to partially counteract the postmenopause-related transcriptional changes . Our results suggest that during the early postmenopausal years , when there is no counteracting medication available , muscle transcriptome changes notably , whereas HRT appears to slow down this phenomenon and could therefore aid in maintaining proper muscle mass and function after menopause
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 .