Vitamin D receptor alleles and bone mineral density in a normal premenopausal Brazilian female population

Abstract

Studies on the association between vitamin D receptor (VDR) polymorphism and bone mineral density (BMD) in different populations have produced conflicting results probably due to ethnic differences in the populations studied. The Brazilian population is characterized by a very broad genetic background and a high degree of miscegenation. Of an initial group of 164, we studied 127 women from the city of São 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 BMD. VDR genotype was assessed by PCR amplification followed by BsmI digestion of DNA isolated from peripheral leukocytes. BMD was measured using 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 native 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 age, height, weight, body mass index or age at menarche. Lumbar spine BMD was significantly higher in the bb group (1.22 ± 0.16 g/cm 2 ) than 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 BB (0.90 ± 0.09) (P<0.05). These data indicate that there is a significant correlation between the VDR BsmI genotype and BMD in healthy Brazilian premenopausal females.

Fractures of the proximal femur: correlation with vitamin D receptor gene polymorphism

“…In agreement with this fact, we did not detect any BB genotype in the 6 individuals of oriental extraction who participated in the present study. Although the number of subjects involved is small, these data agree with those observed in another study conducted on a population of premenopausal women in the city of São Paulo (9), where the B allele was found only in 16.6% of orientals, in contrast to 60.8% of whites and 74.9% of blacks and crossbreds.…”

“…Morrison et al (5) suggested that the alleles of the vitamin D receptor (VDR) may be of high predictive value in the quantification of bone mass in an individual. Although later studies conducted on different racial groups in different countries have produced conflicting results (6-8), we observed the same correlation as that reported by Morrison et al in a population of 126 premenopausal Brazilian women from the city of São Paulo (9). We reported that a group of women with a BB genotype had, on average, a lower bone mineral density (BMD) than women with the bb genotype and this difference was more significant in a region of the neck of the femur.…”

Bone mineral density in young women of the city of São Paulo, Brazil: correlation with both collagen type I alpha 1 gene polymorphism and clinical aspects

“…We first attempted to study the association between vitamin D receptor polymorphism and BMD in a similar population. Lazaretti-Castro et al (27) investigated vitamin D receptor gene polymorphism and BMD in a population of young women from the city of São Paulo and detected lower spinal and femoral BMD in subjects with the BB genotype when compared with the bb genotype.…”

Genetic Determinants of Bone Mass

“…A number of studies have been published over the last 3 years; some were affirmative, in the sense that they described an association between VDR genotypes and BMD, risk of fractures or rates of bone loss [60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77], whereas others did not [56, 57, 78, 79, 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95]. The subject has been debated and revised [18, 19, 20, 21, 22, 23, 24, 25, 96, 97, 98, 99, 100, 101, 102].…”