diabetes hepatocellular carcinoma and mortality in hepatitis cinfected patients a populationbased cohort study background and aim the effect of diabetes mellitus dm on the development of hepatocellular carcinoma hcc and allcause mortality after hcc development in chronic hepatitis c virus hcvinfected patients remains inconclusive this cohort study aimed to investigate these issues using the taiwanese national health insurance research databasemethods we retrieved and enrolled newly diagnosed dm patients with hcv from the longitudinal cohort of diabetes patients database propensity score matchingincluding age sex alcoholrelated liver disease and baseline liver cirrhosiswas used to identify and enroll hcv patients without dm from the longitudinal health insurance database n 1686 a multistate model was used to investigate transitions from starttohcc starttodeath and hcctodeathresults the multistate model showed higher cumulative hazards for starttohcc starttodeath and hcctodeath transitions in the dm vs nondm cohort the cumulative probability of death with or without hcc after 10 years of followup was higher in the dm cohort than in the nondm cohort multivariable transitionspecific cox models demonstrated that dm significantly increased the risk for transition from starttohcc adjusted hazard ratio ahr 136 95 confidence interval ci 116159 p 0001 starttodeath ahr 261 95 ci 205333 p 0001 and hcctodeath ahr 136 95 ci 110168 p 0005 the effect of liver cirrhosis on starttohcc and starttodeath transitions decreased over time particularly within 2 yearsconclusions diabetes mellitus increased the risk of hcc development in hcvinfected patients and the risk of allcause mortality in patients with or without hcc