Vitamin D Receptor Alleles, Bone Mineral Density and Turnover in Postmenopausal Osteoporotic and Healthy Women

Abstract

Objective: Vitamin D receptor (VDR) gene polymorphisms and bone metabolic markers were investigated as potential genetic markers for osteoporosis in postmenopausal Turkish women. The relationship between their VDR gene polymorphisms and bone states was determined. Materials and Methods: Restriction fragment length polymorphisms at the VDR gene locus (i.e., for BsmI, ApaI, and TaqI) was investigated in 75 postmenopausal osteoporotic (53.16 ± 1.31 years) and 66 healthy (52.62 ± 1.69 years) Turkish women and the genotypes were related to bone mineral density (BMD) at femoral neck (FN), lumbar spine (L1–4), trochanter, Ward’s triangle (Ward’s) and metabolic parameters of bone turnover. Results: In osteoporotic women, TaqI genotype-related differences of the VDR gene were found to be significant at all BMD sites; TT genotype had higher L1–4 BMD values than Tt and tt (p < 0.05); tt genotype had significantly lower BMD at FN (p < 0.05), trochanter (p < 0.01), and Ward’s (p < 0.05) compared to TT genotype. The tt genotype was found to be associated with higher (p < 0.05) serum osteocalcin levels compared to Tt and TT genotypes in the osteoporotic women, whereas no such association was found for the healthy women. Conclusion: Our data showed an association between VDR TaqI genotype and BMD at the FN, L1–4, trochanter and Ward’s triangle in nonobese postmenopausal osteoporotic women. Thus the VDR gene Taql polymorphism modulates differences in BMD in the postmenopausal osteoporotic women.

The role of vitamin D receptor gene polymorphisms in the bone mineral density of Greek postmenopausal women with low calcium intake

“…Although this initial finding has been partially withdrawn, in the following years, a large number of studies investigated the potential associations of VDR polymorphisms with BMD in different ethnic populations [4][5][6][7][8][9][10], as well as with other parameters such as bone loss [11,12], fractures [11,13,14] and bone turnover [14][15][16]. However, these studies have provided controversial and inconclusive results due to differences in sample size, ethnic background and age group [17,18].…”

Genetic determinants of bone mass do not relate with breast cancer risk in US white and African-American women

“…There have been numerous studies that have examined the association between differing gene alleles and bone mineral density (BMD), many focusing on osteoporosis [9][10][11][12][13][14]. Using a genetic marker for the vitamin D receptor (VDR) gene, we have previously found ethnic differences in the BMD of African-American and white women and children [15].…”

The relationship between vitamin D receptor (VDR) polymorphism and the occurrence of osteoporosis in menopausal Iranian women

“…In 2009, Dunbar et al studied Turkish menopausal women and showed that individuals with aa genotype had a lower bone density and higher serum calcium level in comparison with those with AA genotype (23). On the other hand, in 2004 in a similar study on Turkish menopausal women with osteoporosis, it was found that individuals with TT, Tt, and tt genotypes (TaqI) had the highest bone density and lowest serum calcitonin level (24). In Greek menopausal women with osteoporosis, none of the polymorphisms of BsmI and TaqI had a significant relationship with bone density (BMD), osteoporosis, and bone fractures, while having a significant relationship with calcium absorption (25).…”