The global epidemiology of non-alcoholic fatty liver disease and non-alcoholic steatohepatitis among patients with type 2 diabetes

Background and aims Nonalcoholic fatty liver disease (NAFLD) now known as metabolic dysfunction associated steatotic liver disease (MASLD) is closely associated with type 2 diabetes (T2D). Our aim was to estimate the most recent global prevalence of NAFLD/MASLD, non-alcoholic steatohepatitis (NASH) now known as metabolic dysfunction associated steatohepatitis (MASH), advanced fibrosis, and mortality among patients with T2D. Methods We systematically searched PubMed and Ovid MEDLINE for terms including NAFLD, NASH, and T2D published 1990-2023 according to PRISMA. The meta-analysis was conducted using a random-effects model. Assessment of bias risk used the Joanna Briggs Institute appraisal tool. Results From 3,134 studies included in the initial search, 123 studies (N=2,224,144 patients with T2D) were eligible. Another 12 studies (N=2,733 T2D patients with liver biopsy) were eligible for histologic assessments. The global pooled prevalence of NAFLD/MASLD among patients with T2D was 65.33% (95% CI, 62.35-68.18%). This prevalence increased from 55.86% (42.38-68.53%) in 1990-2004 to 68.81% (63.41-73.74%) in 2016-2021 (p=.073). The highest NAFLD/MASLD prevalence among T2D patients was observed in Eastern Europe (80.62%, 75.72-84.73%), followed by the Middle East (71.24%, 62.22-78.84%), and was lowest in Africa (53.10%, 26.05-78.44%). Among patients with liver biopsy data, the global pooled prevalence of NASH/MASH, significant fibrosis and advanced fibrosis was 66.44% (56.61-75.02%), 40.78% (24.24-59.70%), and 15.49% (6.99-30.99%), respectively. The pooled all-cause mortality was 16.79 per 1,000 Person Years (PY) (10.64-26.40), 4.19 per 1,000 PY (1.34-7.05) for cardiac-specific mortality; 6.10 per 1,000 PY (0.78-4.88) for extra-hepatic cancer-specific mortality; 2.15 per 1,000 PY (0.00-2.21) for liver-specific mortality. Conclusions The prevalence of NAFLD/MASLD among T2D is high and growing. The majority of NAFLD/MASLD patients with T2D have NASH/MASH and a significant proportion have advanced fibrosis.