Vitamin D Receptor Polymorphisms in Overweight/Obese Chronic Kidney Disease Patients on Dialysis

Background: Little is known about the possible association of vitamin D receptor (VDR) gene polymorphisms in obese patients with chronic kidney disease on dialysis (CKD-G5D). Therefore, we aimed to investigate VDR gene TaqI, ApaI, and FokI single-nucleotide polymorphisms (SNPs) in overweight/obese CKD-G5D patients. Methods: Seventy-one normal-weight and 68 overweight/obese CKD-G5D patients were included in the study. The polymerase chain reaction-restriction fragment length polymorphism method was used for genotyping. Demographic and laboratory data were obtained from the medical records of patients. Results: For all 3 SNPs, no significant association was found between normal-weight and overweight/obese patients ( P > .05). High-density lipoprotein (HDL) concentrations were lower, but triglyceride (TG) and glucose levels were higher in overweight/obese patients compared to normal-weight patients ( P < .001 for HDL and TG and P = .023 for glucose). In overweight/obese patients, individuals with the TaqI CC genotype had higher (PTH) levels than those with TC and TT genotypes (CC = 717.1 +/- 616.4, TC = 342.7 +/- 360.8, and TT = 310.2 +/- 323.4 pg/mL; P = .028). Similarly, patients with the ApaI genotype (627.3 +/- 653.0 mg/dL) had higher TG levels than those with the AA and AC genotypes (CC = 627.3 +/- 653.0, AA = 223.3 +/- 156.6, AC = 193.1 +/- 85.4; P < .001). Overweight/obese patients with the FokI TT genotype had higher glucose concentrations than those with the CC and CT genotypes (CC = 183.4 +/- 128.4 mg/dL, TT = 151.9 +/- 66.1 mg/dL, and CT = 107.6 +/- 41.9 mg/dL; P = .008). Conclusion: Our study suggests that VDR TaqI, ApaI, and FokI polymorphisms are not associated with obesity in CKD-G5D patients. However, they might increase the risk of secondary hyperparathyroidism, dyslipidemia, and hyperglycemia.