Abstract
This study was performed to investigate the relationships of hepatitis B (HBV) and hepatitis C virus (HCV) infection to age-related cataract, and to assess whether liver damage mediates the hepatitis-cataract association. This study analyzed data in the Korea National Health and Nutrition Examination Survey 2010-2012 on 10,037 participants aged ≥40 years. We performed mediation analysis to address the contribution of serum markers of liver damage, high aspartate (AST, >49.9 IU/L) and alanine aminotransferase (ALT, >56.1 IU/L), to the relationships of HBV and HCV infection to cataract. Odds ratios (ORs) for nuclear and any cataract with HBV infection were 1.09 [95% confidence interval (95CI) = 1.02-1.16] and 1.07 (95CI = 1.00-1.14), respectively, compared to HBV uninfection; ORs with HCV infection were 1.35 (95CI = 1.18-1.55) and 1.40 (95CI = 1.12-1.76), respectively. High AST completely mediated the HBV infection-any cataract association. The significant relationships of HCV infection with nuclear and any cataract were formed only by their direct effects, not by mediation effects of high AST or ALT. HBV and HCV infection was significantly associated with nuclear and any cataract. High AST significantly mediates the effects of HBV infections on any cataract outcome, but the associations of HCV infection with nuclear and any cataract were not mediated by high AST or ALT.