Background: Periodontitis and osteoporosis are 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 pre-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 XbaI and PvuII 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 PvuII and XbaI and BMD in post-menopausal and pre-menopausal CP patients, respectively (P >0.05). However, there was association between pre- and 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 PvuII TT genotype presented significantly lower Ward's BMD than the pre-menopausal CP women (P=0.007), meanwhile, the post-menopausal CP women who carried XbaI 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.