Endogenous testosterone concentrations and muscle mass, strength and performance in women, a systematic review of...

To explore the associations between endogenous testosterone blood concentrations and muscle mass, strength and performance in community dwelling women. DESIGN, PATIENTS AND MEASUREMENTS: Online databases, including Ovid MEDLINE, EMBASE and Web of Science, were searched for observational studies, with at least 100 female participants, reporting associations between endogenous testosterone blood concentrations and muscle mass, strength and performance. The findings were synthesized in a narrative review. Heterogeneity in study design and analysis precluded a meta-analysis.

Of the 36 articles retrieved for full-text review, 10 met the inclusion criteria. Eight studies were cross-sectional, 1 longitudinal and 1 provided both cross-sectional and longitudinal data. Testosterone was measured by liquid chromatography-tandem mass spectrometry in two studies and by immunoassay in 8. An association between total testosterone and muscle mass, strength or performance in women was not found. The studies of calculated free or bioavailable testosterone and lean muscle mass reported a positive association, but no association was reported for muscle strength or performance. Each included study was limited by a high risk of bias in at least one assessed domain.

This review does not support an association between testosterone and muscle mass, strength or performance in women. This, together with the reported associations between free or bioavailable testosterone and muscle mass should be interpreted cautiously due to the predominant use of immunoassay and the inaccuracy of calculated variables. Additionally, biological significance of nonprotein bound testosterone has not been established. Further studies examining the relationship between precisely measured testosterone and muscle mass and function in women are required.