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

BACKGROUND: Osteoporosis, a multifactorial disease with reduced bone mineral density which increases the probability of bone fractures, is caused by calcium deficiency, and its incidence increases with age. It has been determined that mutations in functional regions of vitamin D receptor gene will affect the metabolism of minerals especially calcium and, therefore, bone density. The present study evaluates the relation between vitamin D receptor polymorphisms, TaqI (rs731236) and ApaI (rs7975232), and osteoporosis in menopausal Azari women in Zanjan province.

MATERIALS AND METHODS: This case-control study has been conducted on 50 menopausal women suffering from osteoporosis and 50 menopausal women who did not suffer from osteoporosis in Zanjan province. The diagnosis of osteoporosis was confirmed using DEXA instrument. Peripheral blood was collected from the subjects and controls to extract DNA and assess the ApaI and TaqI polymorphisms using PCR-RFLP method. The results were interpreted using independent T-test, chi-square, and Pearson correlation coefficient with a p-value less than 0.05.

RESULTS: There was not a significant difference between the frequency of ApaI (AA/Aa/aa) and TaqI (TT/Tt/tt) genotypes in cases (mean age 68.72) and controls (mean age 64.7) (p=0.37 and p=0.64, respectively). In addition, ApaI/TaqI allele haplotype in osteoporotic population showed non-significant relation (p value=0.563) compared with the control group.

DISCUSSION AND CONCLUSION: The relationship between the genotypes and osteoporosis, cancers, and mineral metabolism disorders has been studied for a long time. Although there has been a significant relation between the aforementioned genotypes and osteoporosis or reduced mineral density-related bone fractures in some studied, some other studies have opposing results. Therefore, it is only possible to reach an acceptable conclusion by studying the haplotype of the polymorphisms in subjects.