Aim: To clarify whether nonalcoholic fatty liver disease (NAFLD) increases the risk of cardiovascular disease.
Methods: We carried out a prospective observational study with a total of 1637 apparently healthy Japanese men and women who were recruited from a health check-up program. NAFLD was diagnosed by abdominal ultrasonography. The metabolic syndrome (MS) was defined according to the modified National Cholesterol Education Program (NCEP) ATP III criteria. Five years after the baseline evaluations, the incidence of cardiovascular disease was assessed by a self-administered questionnaire.
Results: Among 1221 participants available for outcome analyses, the incidence of cardiovascular disease was higher in 231 subjects with NAFLD at baseline (5 coronary heart disease, 6 ischemic stroke, and 1 cerebral hemorrhage) than 990 subjects without NAFLD (3 coronary heart disease, 6 ischemic stroke, and 1 cerebral hemorrhage). Multivariate analyses indicated that NAFLD was a predictor of cardiovascular disease independent of conventional risk factors (odds ratio 4.12, 95% CI, 1.58 to 10.75, P = 0.004). MS was also independently associated with cardiovascular events. But simultaneous inclusion of NAFLD and MS in a multivariate model revealed that NAFLD but not MS retained a statistically significant correlation with cardiovascular disease.
Conclusion: Although both of them were predictors of cardiovascular disease, NAFLD but not MS retained a statistically significant correlation with cardiovascular disease in a multivariate model. NAFLD is a strong predictor of cardiovascular disease and may play a central role in the cardiovascular risk of MS.