Marijuana is not associated with progression of hepatic fibrosis in liver disease: A systematic review and meta-analysis

Background An estimated 22 million adults use marijuana in the USA. The role of marijuana in the progression of hepatic fibrosis remains unclear. Aims We carried out a systematic review and meta-analysis to evaluate the impact of marijuana on prevalence and progression of hepatic fibrosis in chronic liver disease. Patients and methods We searched several databases from inception through 10 November 2017 to identify studies evaluating the role of marijuana in chronic liver disease. Our main outcome of interest was prevalence/progression of hepatic fibrosis. Adjusted odds ratios (ORs) and hazards ratios (HRs) were pooled and analyzed using random-effects model. Results Nine studies with 5 976 026 patients were included in this meta-analysis. Prevalence of hepatic fibrosis was evaluated in nonalcoholic fatty liver disease (NAFLD), hepatitis C virus (HCV), and hepatitis C and HIV coinfection by two, four, and one studies. Progression of hepatic fibrosis was evaluated by two studies. Pooled OR for prevalence of fibrosis was 0.91 (0.72-1.15), I2=75%. On subgroup analysis, pooled OR among NAFLD patients was 0.80 (0.75-0.86), I2=0% and pooled OR among HCV patients was 1.96 (0.78-4.92), I2= 77%. Among studies evaluating HR, pooled HR for progression of fibrosis in HCV-HIV coinfected patients was 1.03 (0.96-1.11), I2= 0%. Conclusion Marijuana use did not increase the prevalence or progression of hepatic fibrosis in HCV and HCV-HIV-coinfected patients. On the contrary, we noted a reduction in the prevalence of NAFLD in marijuana users. Future studies are needed to further understand the therapeutic impact of cannabidiol-based formulations in the management of NAFLD.