Relationship Between Vitamin D Receptor Gene FokI and ApaI Polymorphisms and Serum Levels of Fetuin-A, Vitamin D, and Parathyroid Hormone in Patients on Hemodialysis

Abstract

Introduction. Low fetuin-A and 1,25-hydroxyvitamin D3 (vitamin D) levels accompanied with high intact parathyroid hormone (PTH) contents are associated with cardiovascular disease in dialysis patients. The aim of present study was to evaluate the relationship between vitamin D receptor (VDR) gene FokI and ApaI polymorphisms with serum levels of fetuin-A, vitamin D, and intact PTH in hemodialysis patients.

Materials and Methods. Serum was obtained from 46 stable chronic hemodialysis patients and 43 healthy controls. Serum levels of intact PTH, fetuin-A, vitamin D, calcium, and phosphorus were measured. Genotyping of the VDR gene was performed using standard methods.

Results. Serum fetuin-A and vitamin D levels were significantly lower, whereas serum levels of PTH, calcium, and Phosphorus were higher in the hemodialysis patients than in the healthy controls. The FokI genotypes were more frequent in the hemodialysis patients than the control group (P = .004). With respect to FokI genotypes, intact PTH level was higher among the hemodialysis patients compared to the controls (P = .02). In contrast, vitamin D level was lower in the hemodialysis patients with ApaI genotypes compared to the control group (P = .04).

Conclusions. Our study shows that increased serum level of PTH and decreased fetuin-A and vitamin D levels may increase susceptibility of atherosclerosis in patients with hemodialysis through VDR gene FokI and ApaI polymorphisms.