1Unidad de Infección Viral e Inmunidad, Centro Nacional de Microbiología, Instituto de Salud Carlos III, Majadahonda, Madrid, Spain.
Background and Aims: There is growing evidence that vitamin D is related to chronic hepatitis C (CHC) pathogenicity. We analysed the relationship of vitamin D status with advanced liver fibrosis (ALF) in CHC treatment-naïve patients and sustained virologic response (SVR) in CHC patients on pegylated interferon alpha plus ribavirin (pegIFNα/ribavirin) therapy.
Methods: We performed a meta-analysis of all eligible studies published to date (April, 2014) in PubMed, SCOPUS, LILACS and the Cochrane Library , assessing plasma/serum vitamin D levels related to ALF and/or SVR. Pooled odds ratios were estimated by either fixed or random effects models.
Results: Fourteen studies were selected from the literature search, 7 for ALF (1083 patients) and 11 for SVR (2672 patients). For liver fibrosis, low vitamin D status was related to a diagnosis of ALF, with the cut-offs of 10 ng/mL (OR=2.37 (95%CI=1.20, 4.72)) and 30 ng/mL (OR=2.22 (95%CI=1.24, 3.97)) being significant, and a near-significance for 20 ng/mL (OR=1.44 (95%CI=0.99, 2.12)). Regarding SVR, a significant heterogeneity among studies was found (p<0.001), and we only found a significant association with SVR for a vitamin D cut-off of 20 ng/mL (OR=0.53 (95%CI=0.31, 0.91)). When meta-analysis was performed excluding the outliers, significant pooled ORs were found for all patients [10 ng/mL (OR=0.48 (95%CI=0.34, 0.67)) and 20 ng/mL (OR=0.58 (95%CI=0.45, 0.76))] and GT1/4 patients [10 ng/mL (OR=0.53 (95%CI=0.34, 0.81)) and 20 ng/mL (OR=0.54 (95%CI=0.39, 0.74))].
Conclusions: Low vitamin D status in CHC patients is associated with a higher likelihood of having ALF and lower odds of achieving SVR following pegIFNα/ribavirin therapy.