The global epidemiology of nonalcoholic fatty liver disease (NAFLD) and nonalcoholic steatohepatitis (NASH): a systematic review

Abstract

BACKGROUND AND AIMS: NAFLD is a leading cause of liver-related morbidity and mortality. We assessed the global and regional prevalence, incidence, and mortality of NAFLD using an in-depth meta-analytic approach. APPROACH AND RESULTS: PubMed and Ovid MEDLINE were searched for NAFLD population-based studies from 1990 to 2019 survey year (last published 2022) per Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). Meta-analysis was conducted using random-effects models. Bias risk assessment was per Joanna Briggs Institute. Of 2585 studies reviewed, 92 studies (N=9,361,716) met eligibility criteria. Across the study period (1990-2019), meta-analytic pooling of NAFLD prevalence estimates and ultrasound-defined NAFLD yielded an overall global prevalence of 30.05% (95% CI: 27.88%-32.32%) and 30.69% (28.4-33.09), respectively. Global NAFLD prevalence increased by +50.4% from 25.26% (21.59-29.33) in 1990-2006 to 38.00% (33.71-42.49) in 2016-2019 ( p <0.001); ultrasound-defined NAFLD prevalence increased by +38.7% from 25.16% (19.46-31.87) in 1990-2006 to 34.59% (29.05-40.57) ( p =0.029). The highest NAFLD prevalence was in Latin America 44.37% (30.66%-59.00%), then Middle East and North Africa (MENA) (36.53%, 28.63%-45.22%), South Asia (33.83%, 22.91%-46.79%), South-East Asia (33.07%, 18.99%-51.03%), North America (31.20%, 25.86%-37.08%), East Asia (29.71%, 25.96%-33.76%), Asia Pacific 28.02% (24.69%-31.60%), Western Europe 25.10% (20.55%-30.28%). Among the NAFLD cohort diagnosed without a liver biopsy, pooled mortality rate per 1000 PY was 12.60 (6.68-23.67) for all-cause mortality; 4.20 (1.34-7.05) for cardiac-specific mortality; 2.83 (0.78-4.88) for extrahepatic cancer-specific mortality; and 0.92 (0.00-2.21) for liver-specific mortality. CONCLUSIONS: NAFLD global prevalence is 30% and increasing which requires urgent and comprehensive strategies to raise awareness and address all aspects of NAFLD on local, regional, and global levels.

The authors' abstract, as published at the source. Hepatology, 2023 · DOI ↗