Genotypes of the vitamin-D-receptor gene and bone mineral density in Caucasoid postmenopausal females.

Abstract

To evaluate the relation of bone mineral density (BMD) to inherited polymorphisms within the gene coding for the vitamin D receptor (VDR) in postmenopausal women. DNA samples from 163 post-menopausal women and from 112 controls were genotyped for common allelic determinants within the VDR gene as defined by the restriction enzyme sites for BsmI, ApaI, and TaqI. BMD was evaluated at the lumbar spine (L2-L4) by dual energy X-ray absorptiometry. Single restriction enzyme site polymorphisms as well as their joint genotypes were evaluated for their association with BMD in postmenopausal women. The three restriction site polymorphisms showed a close association indicating linkage disequilibrium (P < 0.0001). There was no relationship between any of the single restriction site polymorphisms and BMD. The distribution of the five most common joint genotypes among postmenopausal women and controls was similar. There was no relation of BMD and any of the five most common VDR genotype groups. Females more than 5 years after menopause had a significantly lower BMD than those less than 5 years after menopause (P < 0.001). This age-related decrease of BMD was also decernible within genotype groups. In our population, the postmenopausal period has a major influence on BMD, but BMD is not controlled significantly by any of the common allelic variations within the VDR gene.