Effects of Gene Variants Controlling Vitamin D Metabolism and Serum Levels on Hepatic Steatosis

Digestion. 2018;97(4):298-308. doi: 10.1159/000485180. Epub 2018 Mar 7.

Abstract

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 <20 ng/mL) occurred in 66% of patients. Median CAP was 296 (100-400) dB/m. Patients with advanced steatosis (CAP ≥280 dB/m) had significantly (p = 0.033) lower 25(OH)D levels as compared to patients with CAP <280 dB/m. Moreover, the rare allele [T] in GC rs7041 was significantly (p = 0.018) associated with higher 25(OH)D levels in patients with CAP <280 dB/m. However, 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.

Keywords: 25-Hydroxyvitamin D; Fatty liver; Gene polymorphisms; Transient elastography.

MeSH terms

  • Adult
  • Aged
  • Aged, 80 and over
  • Alleles
  • Cohort Studies
  • Elasticity Imaging Techniques
  • Fatty Liver / blood
  • Fatty Liver / diagnostic imaging
  • Fatty Liver / genetics*
  • Fatty Liver / metabolism
  • Female
  • Genotype
  • Germany
  • Humans
  • Liver / diagnostic imaging
  • Liver / pathology
  • Male
  • Metabolic Networks and Pathways / genetics*
  • Middle Aged
  • Oxidoreductases Acting on CH-CH Group Donors
  • Polymorphism, Single Nucleotide
  • Vitamin D / analogs & derivatives*
  • Vitamin D / blood
  • Vitamin D / metabolism
  • Vitamin D Deficiency / blood
  • Vitamin D Deficiency / diagnosis
  • Vitamin D Deficiency / genetics*
  • Vitamin D Deficiency / metabolism
  • Young Adult

Substances

  • Vitamin D
  • 25-hydroxyvitamin D
  • Oxidoreductases Acting on CH-CH Group Donors
  • 7-dehydrocholesterol reductase