Lean Metabolic Dysfunction-Associated Steatotic Liver Disease

Goals: To compare outcomes of MASLD in obese and nonobese populations. Background: MASLD is emerging as one of the leading causes of liver failure and liver-related morbidity and mortality, with an increasing prevalence in the nonobese or lean population. The purpose of this study is to compare hepatic and oncological outcomes between MASLD patients with lean BMI and nonlean BMI. Study: The National Inpatient Sample (NIS) was queried from 2016 to 2020 for adult hospitalizations with MASLD. Exclusion criteria included concurrent diagnoses of viral hepatitis, alcoholic hepatitis, primary biliary cholangitis, hereditary hemochromatosis, autoimmune hepatitis, or Wilson disease. Outcomes of MASLD and its complications were compared between the lean and nonlean subgroups. Results: Patients with lean BMI had higher mortality rates (odds ratio: 2.10, P<0.001). The lean cohort also had higher odds of cirrhosis, portal hypertension, SBP, and ascites. The lean subgroup had higher odds of gastrointestinal malignancies including esophageal cancer, gastric cancer, pancreatic cancer, and colorectal cancer. Conclusions: Hospitalized lean MASLD patients had higher odds of mortality, ​​hepatic morbidities, and gastrointestinal malignancies. These results challenge the use of BMI as a predictor of morbidity and mortality for MASLD patients. Future studies should focus on therapeutic options for MASLD and compare their efficacies between lean and nonlean populations.