Association of estrogen receptor beta and estrogen-related receptor alpha gene polymorphisms with bone mineral density in postmenopausal women

摘要

The aim of the study was to investigate the possible association of AluI and RsaI polymorphisms of estrogen receptor beta (ER-beta) gene and 23-bp nucleotide repeat polymorphism of estrogen-related receptor alpha (ERR alpha) gene with bone mineral density (BMD) in postmenopausal Egyptian women. Two-hundred postmenopausal osteoporotic women as cases and 180 healthy age-matched postmenopausal women as controls were genotyped by PCR fragment length polymorphism for AluI, allele-specific PCR for RsaI, and by sizing of PCR products on agarose gels for ERR alpha repeats. sRANKL levels were estimated by ELISA. BMD measurements for spine and femoral neck were performed by dual energy X-ray ab-sorptiometry. A significant difference between women with osteoporosis and controls regarding allele and genotype distributions of AluI G/A (OR 2.37, 95 % CI 1.77-3.18 and p < 0.001 for A allele) and ERR alpha polymorphisms (for the two repeats allele OR 2.08, 95 % CI 1.09-4.00, and p = 0.02). Osteoporotic women with the AluI AA + GA genotype or with the EER alpha 2,2 genotype had significantly lower BMD than did women with the other genotypes. Moreover, there was a significant increase of the mean values of sRANKL in carriers of AluI A, RsaI A alleles and in patients having 2,2 genotypes of ERR alpha (p < 0.001, p < 0.001, p = 0.02, respectively). We demonstrated an association of ER-beta AluI G/A and ERR alpha 23-repeats polymorphisms with BMD in postmenopausal Egyptian women. A possible effect of ER-beta and ERR alpha polymorphisms on the levels of sRANKL was estimated.