Effect of the Vitamin D Receptor Polymorphism on Bone Mineral Density and Bone Metabolism

摘要

Vitamin D Receptor (VDR) polymorphisms are known to affect some aspects of bone metabolism, but the manifestations in a vitamin D deficient population are not that well known.Aim: To assess the effect of VDR polymorphisms on Bone Mineral Density (BMD) and biochemical manifestations of vitamin D deficiency in a vitamin D deficient population.Materials and Methods: Thirty participants with vitamin D deficiency {25 (OH)D=<20 ng/mL} and other biochemical features of vitamin D deficiency, i.e., elevated serum ALP, plasma PTH or decreased serum phosphate, were recruited as cases. Thirty participants with vitamin D deficiency (<20 ng/mL) who had no biochemical features of vitamin D deficiency were recruited as controls. Biochemical investigations and BMD were measured in all participants. VDR polymorphism (Fok1 and Bsm1 ) were analysed with Polymerase Chain Reaction–Restriction Fragment Length Polymorphism (PCR-RFLP) analysis. Chi-Square, Analysis of variance (ANOVA) and Multivariate Analysis Of Variance (MANOVA) are used as statistical analysis.Results: Genotype frequency of Bsm1 and Fok1 were similar among cases and controls. BMD at L3 vertebra (lumbar spine lateral) was higher in Ff genotype of Fok1 , whereas BMD at lumbar spine (L4 vertebra) was lower in bb genotype of Bsm1 . In multivariate analysis BMD at lumbar spine, was affected by genotype of Bsm1 (Bb ). Body Mass Index (BMI) was higher among participants with BB in comparison to bb genotype.Conclusion: An association was found between BMD, BMI and VDR polymorphisms. However, distribution of different VDR polymorphisms was similar among participants who had and who did not have subtle manifestations of vitamin D deficiency.