Assessment of Factors Regulating Androgen Receptor (AR) and Estrogen Receptor Alpha (ERα) Expression in Men with End-Stage Hip Osteoarthritis

This study aimed to identify environmental and hormonal determinants of steroid receptor expression in the bone tissue of men with osteoarthritis. Twenty-six men undergoing total hip arthroplasty were included. Serum hormones, bone turnover markers, and elemental concentrations were assessed, and bone samples were analyzed using immunohistochemistry and multivariate regression models. Results: Estrogen receptor alpha (ERα) expression was a significant positive predictor of the bone formation marker procollagen type I N-terminal propeptide (PINP) (p = 0.0386), indicating its key role in anabolic processes. Androgen receptor (AR) expression showed a positive trend with the resorption marker CTX-I (p = 0.0956). A strong negative association was observed between Body Mass Index (BMI) and ERα expression (β = −0.50; p = 0.0018), suggesting reduced estrogen sensitivity in individuals with higher adiposity. Local accumulation of metals significantly influenced receptor expression. Lead in bone was strongly associated with increased AR expression (β = +1.457; p = 0.0009), whereas manganese was positively associated with ERα expression (β = +2.112; p = 0.0409). These findings indicate that local bone tissue analysis provides more accurate insight into hormonal regulation than serum measurements and highlight the role of environmental factors in modulating bone metabolism in men.