Relationship between VDR Gene Polymorphism and Renal Osteodystrophy in Persistent Hemodialysis Patients

Objective To investigate the relationship between VDR gene polymorphism and bone mineral density (BMD) in patients undergoing maintenance hemodialysis by analyzing the changes in vitamin D receptor (VDR) gene polymorphism. Methods Two hundred patients undergoing maintenance hemodialysis from January 2016 to November 2017 were selected, aged 20-65 years. The BMD of three different genotypes, VDR BB genotype, VDR Bb genotype and VDR bb genotype were measured. The femoral neck BMD was measured with DEXA and the general condition of the patients was investigated. Pearson test was used to analyze the correlation between VDR gene polymorphism and bone metabolism index. Results The Z-score of BMD in VDR bb genotype was lower than that in VDR Bb genotype, while that in VDR Bb genotype was lower than that in VDR BB genotype. Amongst the Z-score values of BMD in maintenance hemodialysis patients with different genotypes, the difference was statistically significant (P<0.05). The incidence of low bone mass and bone mineral deficiency in patients with maintenance hemodialysis was 30.0% and 20.0%, respectively. For different VDR genotypes, the prevalence of low bone mass and bone mineral deficiency in patients with maintenance hemodialysis was significantly different (P<0.05). There was significant difference in the bone metabolic parameters (calcium, phosphorus, ALP and PTH) between VDR BB and VDR Bb (P<0.05). The BMD of maintenance hemodialysis patients was related to body weight (r=-0.260, P<0.05), but not with age or height. Conclusions Renal bone dystrophy in patients with chronic maintenance hemodialysis is affected by genetic factors. BsmI polymorphism of VDR gene affects bone metabolism. VDR gene polymorphism can be used as a predictor of renal bone dystrophy and provide reference for clinical treatment.