Correlation of estrogen receptor alpha gene polymorphisms and bone mineral density in Chinese women with chronic periodontitis

Background Periodontitis and osteoporosis aro one of the frequently encountered diseases in post-menopausal women. Estrogen receptors (ERs) regulated bone metabolism. To investigate the possible effect of ER-alpha (α) gene polymorphisms on bone mineral density (BMD) in pre- and post-menopausal Chinese women with chronic periodontitis (CP), we provided sufficient quantitative information concerning the correlation between ER gene polymorphisms and BMD in periodontitis.Methods Sixty-five post-menopausal and eighty pro-menopausal CP women, and sixty post-menopausal healthy individuals were recruited in this study. Genomic DNA was extracted from oral mucosa swab sample of each subject by the Chelex-100 method. Determination of the ER-α polymorphisms was performed by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) technique with Xbal and Pvull enzyme. The index for periodontal examination includes clinical attachment loss (CAL) and probing pocket depth (PPD). BMD was measured by dual-energy X-ray absorptiometry (DEXA).Results There were no significant differences between the ER-(α genotypes of Pvull and Xbal and BMD in post-menopausal and pro-menopausal CP patients, respectively (P ＞0.05). However, there was association between preand post-menopausal CP patients at BMD of lumbar spine L2-L4 (P=0.027) and Ward's BMD (P=0.004). Furthermore, the post-menopausal CP women who carried Pvull ∏ genotype presented significantly lower Ward's BMD than the pre-menopausal CP women (P=0.007), meanwhile, the post-menopausal CP women who carried Xbal AA genotype presented significantly lower spine L2-L4 BMD than the pre-menopausal CP women (P=0.003).Conclusions ER-(α gene polymorphisms may be a susceptible indicator for BMD variation of lumbar spine L2-L4 and Ward in Chinese pre- and post-menopausal women patients with CP.