VITAMIN-D-RECEPTOR ALLELES AND BONE-MINERAL DENSITY IN A NORMAL PREMENOPAUSAL BRAZILIAN FEMALE-POPULATION

Studies on the association between vitamin D receptor (VDR) polymorphi sm and bone mineral density (BMD) in different populations have produc ed conflicting results probably due to ethnic differences in the popul ations studied. The Brazilian population is characterized by a very br oad genetic background and a high degree of miscegenation. Of an initi al group of 164, we studied 127 women from the city of Sao Paulo, aged 20 to 47 years (median, 31 years), with normal menses, a normal diet and no history of diseases or use of any medication that could alter B MD. VDR genotype was assessed by PCR amplification followed by BsmI di gestion of DNA isolated from peripheral leukocytes. BMD was measured u sing dual energy X-ray absorptiometry (Lunar DPX) at the lumbar site ( L2-L4) and femoral neck. Most of the women (77.6%) were considered to be of predominantly European ancestry (20.6% of them reported also nat ive American ancestry), 12.8% were of African-Brazilian ancestry and 9 .6% of Asian ancestry, 41.0% (52) were classified as bb, 48.8% (62) as Bb and 10.2% (13) as BB. The BB, Bb and bb groups did not differ in a ge, height, weight, body mass index or age at menarche. Lumbar spine B MD was significantly higher in the bb group (1.22 +/- 0.16 g/cm(2)) th an in the BB group (1.08 +/- 0.14; P<0.05), and the Bb group presented an intermediate value (1.17 +/- 0.15). Femoral neck BMD was higher in the bb group (0.99+/-0.11 g/cm(2)) compared to Bb (0.93+/-0.12) and B B (0.90+/-0.09) (P<0.05). These data indicate that there is a signific ant correlation between the VDR BsmI genotype and BMD in healthy Brazi lian premenopausal females.