Early and late postmenopausal bone loss is associated with BsmI vitamin D receptor gene polymorphism in Japanese women

To determine whether vitamin D receptor (VDR) gene polymorphisms are associ ated with bone mineral density (BMD) and bone loss in the Japanese populati on, VDR BsmI RFLPs were analyzed in 191 postmenopausal Japanese women by co mparing B allele and b allele DNA sequences, and a point mutation was confi rmed. We examined VDR BsmI restriction fragment length polymorphism (RFLP) with an amplification refractory mutation system (ARMS) using this point of mutation. The frequency of VDR BsmI alleles in the Japanese population was significantly different from that in whites. The bb genotype was identifie d in 79.6%, of the subjects, the Bb genotype in 19.3%, and the BE genotype was in only 1.1%. We find no significant differences in lumbar spine baseli ne BMD between the bb genotype and the Bb genotype. In both early and late postmenopausal periods, serial measurements of vertebral BMD revealed that subjects with the Bb genotype lost BMD faster than those with the bb genoty pe (P = 0.001). We conclude that there is a significant relationship betwee n RFLPs of BsmI VDR and the annual rates of bone loss during early and late postmenopausal periods in the Japanese population.