Nonalcoholic Fatty Liver Disease and Risk of Myocardial Infarction and Stroke in Young Adults: A Nationwide Population-Based Study

Background: Nonalcoholic fatty liver disease (NAFLD) is associated with increased risk of cardiovascular diseases (CVDs). Because studies of young adults are limited, we investigated the relationship between NAFLD and cardiovascular events among a nationally representative sample of young adults in Korea. Methods: This population-based cohort study from the Korean National Health Insurance Service included adults who were 20–39 years old when they underwent a health examination from 2009–2012. NAFLD was defined as fatty liver index (FLI) ≥60, and participants were divided into three groups according to FLI (−59, and ≥60) to investigate the effect of steatosis by grade. Results: Among 5,324,410 participants, 9.8% had an FLI ≥60. There were 13,051 myocardial infarctions (MI, 0.39%) and 8,573 strokes (0.26%) during a median follow-up of 8.4 years. In multivariable analysis, NAFLD was associated with a higher risk of MI and stroke (hazard ratio [HR]=1.69; 95% confidence interval [CI]: 1.61−1.77 and HR=1.73; 95% CI: 1.63−1.84, respectively). MI and stroke had dose-depended relationships with FLI (HR=1.28 in FLI 30−59 and 1.73 in FLI ≥60 for MI and HR=1.18 in FLI 30−59 and 1.41 in FLI ≥60 for stroke, respectively).Conclusions: NAFLD was an independent predictor of MI and stroke in young adults. These results suggest that primary prevention of CVD should be emphasized in young adults with NAFLD.