Lean MASLD and Cardiovascular Disease: A Review.

Metabolic-associated steatotic liver disease (MASLD), formerly known as nonalcoholic fatty liver disease, is prevalent worldwide and is highly associated with cardiovascular disease (CVD). Lean MASLD is defined by hepatic steatosis and cardiometabolic risk factors in individuals with a body mass index below 25 in Western populations or below 23 in Asian populations. Paradoxically, some studies indicate that lean MASLD is associated with an elevated risk of cardiovascular (CV) disease and CV mortality compared with nonlean MASLD. Lean MASLD patients exhibit distinctive metabolic, genetic, and microbiome profiles contributing to increased visceral adiposity, sarcopenia, hepatic fibrosis, systemic inflammation, and endothelial dysfunction. This review examines the epidemiology, pathophysiology, and CV outcomes associated with lean MASLD, addressing discrepancies in the literature. Furthermore, it highlights current clinical guidelines, emphasizes lifestyle modifications, and discusses emerging pharmacotherapies as potential treatment options.