Effects of gene variants controlling vitamin D metabolism and serum levels on hepatic steatosis

Background/Aims: Common genetic variations in vitamin D metabolism are associated with liver stiffness. Whether these genes are implicated in hepatic steatosis remains unclear. Here we aimed to analyse the association of common vitamin D pathway gene variants with liver steatosis. Methods: Liver steatosis was assessed non-invasively in 241 patients with chronic liver conditions by controlled attenuation parameter (CAP). The following polymorphisms were genotyped using TaqMan assays: group-specific component (GC) rs7041, 7-dehydrocholesterol reductase (DHCR7) rs12785878, cytochrome P450 2R1 (CYP2R1) rs10741657, ­vitamin D receptor (VDR) rs7974353. Chemiluminescence immunoassay determined serum 25-hydroxyvitamin D (25(OH) D) concentrations. Results: Vitamin D deficiency (defined by 25(OH)D concentrations p = 0.033) lower 25(OH)D levels as compared to patients with CAP GC rs7041 was significantly (p = 0.018) associated with higher 25(OH)D levels in patients with CAP GC, DHCR7, CYP2R1, and VDR polymorphisms were not related to liver steatosis and obesity traits. Conclusions: Higher CAP values are associated with low serum 25(OH)D concentrations but not with common vitamin D pathway gene variants.