Interaction between ESRα polymorphisms and environmental factors in osteoporosis.

We hypothesized that environmental factors might affect the relationship between genetic predisposition and the risk of bone mineral density (BMD) loss. Cases were 114 Japanese women with a confirmed diagnosis of postmenopausal osteoporosis and controls were 171 general Japanese women. Genetic risk of SNPs in the estrogen receptors was analyzed by a case-control study. The interaction between gene and environmental factors for osteoporosis were assessed by a case-only design. Significant increases in osteoporosis risk were observed with minor alleles of rs2077647 located in the first exon and rs2234693 located in the first intron of estrogen receptor α (ESRα). Haplotype CC at these risk SNPs was strongly associated with osteoporosis risk (odds ratio [OR] =  3.15, 95% confidence interval [CI] = 1.83-5.41). There was a statistically significant interaction between haplotype CC and alcohol drinking; moderate alcohol consumption decreased genetic risk of osteoporosis (OR  =  0.22, 95%CI  =  0.05-0.83).