The influence of correction of vitamin D deficiency on the formation of the stable virological
 response during therapy of genotype-1 chronic hepatitis C with PEGylated interferon-alpha-2 and ribavirin

Abstract

Aim. To study effects of correction of vitamin D deficiency on the outcome of antiviral therapy (AVT) with PEGylated interferon alpha 2 (peg-IFN-α-2) and Ribavirin (RBV) in patients with genotype -1 chronic hepatitis C (CHC-1). Materials and methods. The study included 90 patients with primary HCV-1 and deficiency of vitamin D. In all patients of them, insulin resistance (HOMA-IR), body mass index (BMI), viral load, vitamin D levels, stage of liver fibrosis and polymorphism of the IL-28B gene were evaluated. Antiviral therapy included PEG-IFN-α-2 and RBV in combination with water-soluble vitamin D at a dose of 2000 mg/day. 55 patients were assigned to HCV-1 (study group). 35 patients with CHC-1 (control group) were given only PEG-IFN-α-2 + RBV. Results. Vitamin D level was inversely correlated with HOMA-IR, BMI (R = -0,5; R = -0,5; R = -0,4; respectively, p <0.05, Spearman) and inverse relationship between the level of vitamin D (25-Oh), BMI and HOMA-IR (β for BMI=-0,433 (95% CI -1,863;-0,697, p<0.001), HOMA-IR=-0,252 (95% Cl -1,873;-0,229, p=0,013) was documented based on the multiple regression analysis. In the study group, sustained virological response (SVR) was achieved in 74.5% of the patient compared with 42.9% in the control group; OR SVR in patients of the study group was 6.8 (95% Cl 2,90-16.09, p=0.002). SVR was reached in 66.7% and 22.2% patients of the study group with BMI>25 kg/m2 and controls respectively. OR SVR in patients with BMI over 25 kg/m2 who received cholecalciferol at AVT was 7.0 (95% Cl 1.66-29,23, p=0.01, Fisher test). In the patients with HOMA-IR>2.0, the frequency of SVR in the study qnd control groups was 66.7% and 37.5% respectively; OR SVR in patients with HOMA-IR>2.0 receiving colecalciferol at AVT was 3.3 (95% Cl 1.1-9.9, p=0.03, Fisher's exact test). In the study group a statistically significant decrease of HOMA-IR (p<0.001, Wilcoxon test) and undesirable effects of antiviral therapy (р<0,05) was documented. Conclusions. The addition of colecalciferol at a daily dose of 2000 IU to PEG-IFN-alpha-2+RBV therapy is safe and significantly increases the efficiency of AVT from 40.0 up to 74.5% (p=0.002), improves OR SVR up to 7.0 (95% Cl 1.66-29,23, p=0.01) in patients with BMI >25 kg/m2 and up to 3.3 (95% Cl 1.1-9.9, p=0.03) in patients with HOMA-IR>2; it significantly reduces HOMA-IR (p<0,0001) and the frequency of adverse effects (p<0.05).