Metabolic dysfunction-associated steatotic liver disease increases cardiovascular disease risk in young adults.

Although a robust association between metabolic dysfunction-associated fatty liver disease (MASLD) and cardiovascular disease (CVD) has been established, the impact of MASLD on CVD risk in young adults has not been fully evaluated. This population-based study included adults aged 20-39 years who underwent health screening examinations from 2009 to 2012 based on Korean National Health Insurance Service database. MASLD was defined as a fatty liver index ≥ 30 without any other cause of steatosis, and presence of one or more cardiometabolic risk factors. The primary outcome was newly developed CVD, including myocardial infarction, ischemic stroke, and congestive heart failure. During the median 10.6 years of follow-up, MASLD was observed in 1,435,659 (25.3%) of the 5,666,728 participants. Cumulative incidence of major adverse cardiovascular events was significantly higher in individuals with MASLD compared those without steatosis (P < 0.001). The adjusted hazard ratio (HR) for myocardial infarction was 1.23 [95% CI (confidence interval): 1.18-1.27] in individuals with MASLD compared to those without steatosis. The HR for ischemic stroke and congestive heart failure were higher in individuals with MASLD compared to those without steatosis (HR, 1.12; 95% CI, 1.07-1.17 and HR, 1.18; 95% CI, 1.15-1.21, respectively]. In the subgroup analysis, the elevated HR for CVD in the MASLD group was prominent among individuals who were female and obese. MASLD was associated with an increased risk of CVD in young adults. These findings highlight the need for early intervention in patients with MASLD before they reach middle to reduce the risk of CVD, particularly among young adults in South Korea.