Relation of the estrogen receptor and vitamin D receptor polymorphisms with bone mineral density in postmenopausal Mexican-mestizo women.

BACKGROUND: Since osteoporosis is a complex disease characterized by low bone mineral density (BMD), which is determined by an interaction of genetics with metabolic and environmental factors, the aim of this study was to analyze the possible association among one polymorphism of VDR and two polymorphisms of ESR1; as well as their haplotypes with BMD in postmenopausal Mexican-mestizo women.

METHODS: We studied 742 postmenopausal Mexican-mestizo women. A structured questionnaire for risk factors was applied and BMD was measured in the lumbar spine and total hip by dual-energy X-ray absorptiometry. DNA was obtained from blood leukocytes. One polymorphism of VDR (rs11568820) and two of ESR1 (rs2234693 and rs9340799) were studied. Real-time PCR allelic discrimination was used for genotyping. The differences between the means of the BMDs according to genotype were analyzed with covariance. Hardy-Weinberg equilibrium was tested. Pairwise linkage disequilibrium between single nucleotide polymorphisms was calculated by direct correlation r(2); haplotype analysis was conducted.

RESULTS: Rs9340799 of ESR1 and one haplotype formed by the two polymorphisms of the ESR1 were significantly associated with FN-BMD variations. Moreover, analysis of the genotype of rs11568820 of VDR and the rs2234693 of ESR1 showed no significant differences with BMD variations.

CONCLUSIONS: Our results showed that rs9340799 and one haplotype of ESR1 were significantly associated with BMD only at the femoral neck and this association remained after adjusting for covariates.