Systematic review with meta‐analysis: extrahepatic manifestations in chronic hepatitis C virus‐infected patients in East Asia

SUMMARY Background Although the prevalence of extrahepatic manifestations of chronic hepatitis C virus (HCV) infection has been reported from Western countries, their prevalence in East Asian countries is not well known. Aim To perform a systematic review to quantify the prevalence of selected extrahepatic manifestations of HCV among patients from East Asia. Methods Medline, CINAHL, EMBASE, Cochrane and country‐specific databases were reviewed according to standard guidelines for meta‐analyses. Only articles with patients from East Asian countries were included. Results After review, 34 articles were selected (Japan = 9; China = 5, Korea = 3, Taiwan = 16, multiple countries = 1) with 646 228 subjects, 66 436 with HCV. Mean age for HCV‐infected patients was 56 years (range 41‐72 years), 50% were male (range 26%‐73%). The pooled prevalence of type 2 diabetes in East Asian HCV patients was 19.0% (95% confidence interval 15.6%‐22.9%) (n = 19 studies) with an increased risk when compared to non‐HCV: odds ratio (OR) 1.58 (1.28‐1.94). The prevalence of chronic kidney disease in HCV was 9.2% (5.0%‐16.2%) (n = 7 studies), also with a significantly increased risk: OR=1.98 (1.41‐2.77). Pooled prevalence of cardiovascular disease in HCV was 8.6% (3.5%‐19.9%) (n = 6 studies), also with an increased risk: OR = 1.55 (1.21‐1.98). The prevalence of lichen planus in HCV was 8.9% (3.6%‐20.6%) (n = 6 studies) while the prevalence of rheumatoid arthritis was 4.5% (0.6%‐25.7%) (n = 4 studies). Conclusions These data show increased risk of developing extrahepatic manifestations in East Asian patients with HCV. Both hepatic and extrahepatic manifestations of the infection should be used to accurately determine the total burden of the disease in the region.