Sex difference in the interaction of alcohol intake, hepatitis B virus, and hepatitis C virus on the risk of cirrhosis

Background: The joint effect of the interaction of alcohol intake, hepatitis B virus (HBV) and hepatitis C virus (HCV) on the risk of cirrhosis is still unexplored because a large sample size is required for this investigation. Objective: Evaluation of interaction of HBV, HCV and alcohol abuse on the risk of cirrhosis. Design: We analysed 12,262 consecutive patients with chronic liver disease of various aetiologies referring to 95 Italian liver units in 2001 or 2014. To evaluate the interaction between alcohol abuse, HBV infection, and HCV infection, patients unexposed to either factors were used as reference category. Adjustment for BMI and age was done by multiple logistic regression analysis. Results: Females were older than males (p<0.01) and less frequently showed HBV and alcoholic aetiology (p<0.01). In both sexes, an overtime increasing age and an increasing proportion of subjects with liver cirrhosis was observed, reflecting a better survival (0.01). An additive interaction is observed in females: the O.R. generated by the simultaneous presence of HBV, HCV, and alcohol (5.09; 95% C.I. 1.06–24.56) exceeds the sum (4.14) of the O.R. generated by a single exposure (O.R. = 0.72 for HBsAg positivity, OR = 1.34 for anti-HCV positivity, and O.R. = 2.08 for alcohol intake). No interaction is observed in male sex. Conclusions: The observed gender difference suggests that the simultaneous presence of HBV/HCV coinfection and risky alcohol intake enhances the mechanism of liver damage to a greater extent in females than in males.