Sex steroids and women's physical performance in midlife: Findings from the Menarche-to-PreMenopause Study.

Context: Sex steroids regulate various processes in reproductive and non-reproductive systems, but relationships with physical function in females remain unclear.

Objective: To investigate the associations of oestrogen, androgen, and sex hormone-binding globulin (SHBG) concentrations with performance-based physical function tests among middle-aged Australian women.

Methods: Cross-sectional study with 484 women aged 44.6 ± 1.6 years from the Menarche-to-PreMenopause Study. Oestrogen (oestrone and oestradiol) and androgen (testosterone, DHT, and DHEA) concentrations were measured using liquid chromatography-mass spectrometry. SHBG was measured with immunoassays. Performance was measured by handgrip strength, chair rise and standing balance tests. Participants in the lowest tertile were classified as "low performance". Linear and logistic regression models were used to evaluate associations between log-transformed sex hormones and performance.

Results: In the linear regression analysis, a negative association between oestrone concentrations and chair rise performance was observed after minimal adjustment for clinic location, age, height, and weight (fully adj. coef. -0.2; 95% CI: -0.3, -0.002). Results from the logistic regression showed 30% lower odds of worse standing balance with higher DHT (95% CI: 0.6, 0.9) and SHBG concentrations (95% CI: 0.5, 0.9). No other significant associations were observed in the fully adjusted models.

Conclusion: Findings from this study suggest that oestrone was negatively associated with chair rise performance, whereas DHT and SHBG concentrations were positively associated with standing balance performance among Australian women in their forties. While sex steroids seem to be closely related to performance, other factors, such as age and body size, may influence those associations.