Vitamin D and estrogen receptor gene polymorphism and their interaction associated with bone mineral density in Korean postmenopausal women / 대한내과학회지

ABSTRACT

BACKGROUND: Strong genetic components to the determination of bone mineral density (BMD) have been suggested by family and twin studies. However, association between gene polymorphism and BMD was not consistent in Korean as well as other ethnic groups. The goal of present study is to evaluate the relationship between vitamin D receptor (VDR) and/or estrogen receptor (ER) gene polymorphism and BMD after adjusting for suggested confounding factors and the possibility of VDR gene by ER gene interaction which could impact the bone mass of Korean postmenopausal women. METHODS: We determined the VDR and ER genotypes using a polymerase chain reaction based Bsm I restriction length fragment polymorphism (RFLP) and Pvu II and Xba I RFLP respectively, in a population based DNA sample of 132 Korean postmenopausal women aged 45 to 71. And then related the VDR and ER genotypes to BMD, bone related hormones, biochemical bone markers, and clinical characteristics in these women. Multiple regression analysis was used to predict variables contributing to BMD. Age, height, weight, years since menopause, VDR B genotype, and ER P and X genotypes were used as independent variables. RESULTS: There was no significant relationship of VDR or ER genotypes to lumbar or femoral neck BMD, hormones, and bone turnover markers. However, after controlling for potential confounding factors, a statistically significant ER X genotype effect on femoral neck BMD (p=0.038), but not on lumbar BMD was observed. Moreover, there was more significant effect on femoral neck BMD by an interaction of VDR B * ER X genotype (p=0.013) in multiple regression analysis. CONCLUSION: The ER X genotype was associated with femoral neck BMD in Korean postmenopausal women. This association was more significant with the VDR B genotype interaction.