Vitamin D receptor (VDR) gene polymorphism and vascular dementia due to cerebral small vessel disease in an Asian Indian cohort

Vitamin D receptor (VDR) and its ligand Vitamin D, play a crucial role in regulating multiple pathways for maintaining vascular health. The present study aimed at evaluating whether single nucleotide polymorphisms in VDR gene were associated with susceptibility to vascular dementia (VaD) due to cerebral small vessel disease (SVD). A total of 644 subjects (302 patients diagnosed with cerebral SVD-associated VaD and 342, age- and gender-matched healthy controls) were genotyped for VDR gene variants, FokI, ApaI, TaqI and BsmI, by PCR-RFLP method. Among the 4 examined VDR variants, the presence of the minor allele (Ff+ff vs FF) of FokI variant increased the risk for cerebral SVD by 1.5-fold in men (p = 0.047). Serum 25-hydroxyvitamin D [25(OH)D] was lower in subjects having the FokI “ff” genotype compared to those with the “FF” genotype (p = 0.044). Moreover, in subjects with low serum 25(OH)D the presence of “ff” genotype increased the odds of SVD by 2.5 folds (p = 0.041). ApaI polymorphism decreased the risk of cerebral SVD in women. The distribution of TaqI and BsmI variants were not significantly different between patients and controls. Further studies in large cohorts are necessary to validate the role of FokI polymorphism in cerebral SVD and VaD etiopathogenesis.