BMP7 gene polymorphisms are not associated with bone mineral density or osteoporotic fractures in postmenopausal Chinese women

Aim： A previous study shows that bone morphogenetic protein 7 （BMP7） gene polymorphisms are associated with bone mineral density （BMD） in 920 European Americans. To determine the association of BMP7 polymorphisms and BMD and osteoporotic fracture susceptibility, we performed a case-control association study in postmenopausal Chinese women with or without osteoporotic fracture. Methods： A total of 3815 unrelated postmenopausal Chinese women （1238 with osteoporotic fracture and 2577 healthy controls） were recruited. BMDs of the lumbar spine 1-4 （L1-4） and proximal femur （including total hip and femoral neck） were measured using dual-energy X-ray absorptiometry. Eight tagging single nucleotide polymorphisms （SNPs） in BMP7 gene, including rs11086598, rs4811822, rs12481628, rs6025447, rs230205, rs17404303, rs162316 and rs6127980, were genotyped. Results： Among the 8 SNPs, rs6025447 and rs230205 were associated with total hip BMD （P=0.013 and 0.045, respectively）. However, the associations became statistically insignificant after adjusting for age, height and weight. The TGTG haplotype of BMP7 gene was associated with total hip BMD （P=0.032）, even after adjusting for age, height and weight （P=0.048）; but the association was insignificant after performing the Bonferroni multiple-significance-test correction. Moreover, the 8 SNPs and 9 haplotypes of BMP7 gene were not associated with L1-4 or femoral neck BMD or osteoporotic fracture. Conclusion： This large-sample case-control association study suggests that the common genetic polymorphisms of BMP7 gene are not major contributors to variations in BMD or osteoporotic fracture in postmenopausal Chinese women.