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), I=75%. On subgroup analysis, pooled OR among NAFLD patients was 0.80 (0.75-0.86), I=0% and pooled OR among HCV patients was 1.96 (0.78-4.92), I=77%. Among studies evaluating HR, pooled HR for progression of fibrosis in HCV-HIV co-infected patients was 1.03 (0.96-1.11), I=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.