Metabolic syndrome and the incidence of hepatocellular carcinoma: a meta-analysis of cohort studies

Background: Patients with metabolic syndrome (MetS) were suggested to have a higher risk of hepatocellular carcinoma (HCC), although the results of previous cohort studies are not consistent. Aim: To perform an updated meta-analysis to evaluate the association between MetS and subsequent incidence of HCC. Methods: Relevant cohort studies were identified by searching PubMed and Embase databases. Cochrane's Q-test and I2 statistic were used to analyze the heterogeneity. Random effects model was used for the meta-analysis. Results: Six cohort studies with 127,198 participants and 1,293 HCC cases during follow-up were included. Patients with MetS had a significantly higher incidence of HCC in studies with MetS defined by the revised National Cholesterol Education Program's Adults Treatment Panel III (risk ratio [RR]: 1.43, 95% CI: 1.19-1.72, p<0.001; I2=29%) or International Diabetes Federation criteria (RR: 1.59, 95% CI: 1.13-2.23, p=0.008; I2=0%). Results of subgroup analysis showed that the presence of MetS was associated with a higher incidence of HCC in males (RR: 1.75, 95% CI: 1.28-2.38, p<0.001) but not in females (RR: 1.18, 95% CI: 0.76-1.84, p=0.46), and the association between MetS and higher risk of HCC was consistent regardless whether alcohol intake was adjusted. Although both were significant, MetS conferred higher risk of HCC in carriers of hepatitis B virus when compared with general population (p=0.06). Conclusion: The presence of MetS is associated with significantly increased incidence of HCC in male participants.