Effects of vitamin D receptor gene polymorphisms on susceptibility to disease and bone mineral density in Turkish patients with type 1 diabetes mellitus.

ABSTRACT

BACKGROUND: Vitamin D receptor (VDR) gene is regarded as one of the candidate genes for type 1 diabetes mellitus (T1D) susceptibility and of some genetic factors involved in the development of osteoporosis in this group. STUDY DESIGN: We characterized the VDR gene polymorphism (BsmI, ApaI, TaqI, FokI and Cdx-2 binding site) in a group of Turkish patients with T1D (n=90) and correlated respective VDR genotypes with the bone mass and some parameters of bone turnover. RESULTS: There were no differences in the genotype frequencies of the BsmI, ApaI, TaqI and Cdx-2 polymorphisms in patients and control subjects. We found a significantly higher prevalence of the F allele/the FF genotype in the patients compared to controls (p=0,0031, odds 1.96 (1,27-3,01)). We observed no difference in markers of bone turnover (Serum levels of osteocalcin, PINP and alkaline phosphatase, urinary levels of calcium/ creatinine and N-telopeptid) among different VDR genotypes. No correlation was found between VDR polymorphisms and DEXA measurements of these patients. CONCLUSIONS: Although the FF genotype was found to be a risk factor in a Turkish population, elucidation of this result is necessary in other larger study groups drawn from the same ethnic population.