Association of baseline vitamin D level with genetic determinants and virologic response in patients with chronic hepatitis B

Abstract

Aim: The role of vitamin D in individuals with chronic hepatitis B (CHB) is unclear. We aimed to explore the association of baseline vitamin D level with genetic determinants and week-104 treatment outcome in CHB patients. Methods: Baseline serum 25-hydroxycholecalciferol (25(OH)D) levels and genetic polymorphism within GC, DHCR7, and CYP2R1 were determined in stored serum of 560 patients who were enrolled into a multicenter, randomized, controlled study and completed 104 weeks of telbivudine monotherapy or telbivudine-based optimized therapy. Virologic response was defined as hepatitis B virus DNA <300 copies/mL (52 IU/mL) at week 104. Results: The mean 25(OH)D value was 29.64 ng/mL. The percentage of patients with vitamin D insufficiency (<30 ng/mL) and vitamin D deficiency (<20 ng/mL) were 55.0% and 20.9%, respectively. Gender, season, latitude, and GC rs2282679 polymorphism were independent factors of vitamin D status. Patients with sufficient vitamin D (≥30 ng/mL) achieved a higher virologic response rate than those with vitamin D insufficiency (81.7% vs. 67.2%, P < 0.001). The area under the curve of 25(OH)D to predict virologic response was 0.65 (P < 0.001; 95% confidence interval, 0.62–0.67). On multivariate analysis, 25(OH)D level was an independent predictor of virologic response, but not associated with hepatitis B envelope antigen (HBeAg) seroconversion or alanine aminotransferase (ALT) normalization. Conclusions: Vitamin D insufficiency was highly prevalent in treatment-naïve CHB patients in mainland China. Latitude and genetic determinants affect vitamin D status. Baseline vitamin D level can predict week-104 virologic response, but not HBeAg seroconversion or ALT normalization.