Association between estrogen receptor alpha polymorphisms and equol production, and its relation to bone mass

To investigate the relationship between estrogen receptor polymorphisms and equol production and its effect on bone turnover, 139 workers (mean age 38.3+/-11.1 years) in Japan were recruited. Bone mineral density (BMD), bone turnover markers, and serum equol were measured at a health examination. DNA samples were prepared to detect the estrogen receptor alpha (ERalpha) polymorphism and were digested by PvuII. The number of equol producers was 57. No statistically significant differences were observed in bone mineral density and bone turnover markers between each ERalpha polymorphism and equol production. Since the adjusted odds ratio indicated that interaction itself decreased the risk of osteosono-assessment index (OSI) reduction using logistic regression analysis, further analysis was performed divided by each ERalpha polymorphism. Although the crude odds ratio showed no relationship between equol producers and non-producers, the adjusted odds ratio showed that equol producers with ERalpha pp had a significantly decreased risk of OSI reduction. Although this study was cross-sectional, both equol production and ERalpha polymorphism are closely associated with each other in relation to BMD.