This was a retrospective study.
This study included hemodialysis patients from the Renal Unit of Ghent University Hospital (Ghent, Belgium) and the Algemeen Stedelijk Ziekenhuis Geraardsbergen Hospital (Geraardsbergen, Belgium).
One hundred and ninety-one hemodialysis patients and 211 healthy subjects were recruited from the hemodialysis database. The DBP phenotypes were determined by polyacrylamide gel electrophoresis. Serum DBP, parathyroid hormone, 25-hydroxyvitamin D3, 1,25-dihydroxyvitamin D3, calcium, albumin, and phosphate were measured. Information regarding the intake of vitamin D analogues was collected.
The phenotypic distributions of DBP were in agreement with Hardy-Weinberg equilibrium. Comparing allele frequencies of the two groups, there was an increased proportion of the DBP 2 allele in hemodialysis patients (P < .05). The median serum DBP concentration was lowest in the DBP 2-2 group. The need for oral vitamin D differed significantly (P < .01) between DBP phenotypes, and was greatest in DBP 2-2.
The present study demonstrates an altered DBP allele frequency in hemodialysis patients, compared with the general population. More importantly, vitamin D intake differs depending on the DBP polymorphism, and is greatest for end-stage renal disease patients with a DBP 2-2 phenotype. Therefore, vitamin D treatment deserves more careful monitoring among DBP 2-2 patients with end-stage renal disease.