The relationship between nonalcoholic fatty liver disease and the severity of coronary artery disease in patients with metabolic syndrome

Objectives: Nonalcoholic fatty liver disease (NAFLD) is an important complication of metabolic syndrome (MS). We investigated the possible relationship between NAFLD and angiographical severity of coronary artery disease (CAD) in patients with MS. Study design: This prospective study included 80 patients (35 men, 45 women; mean age 63 +/- 10 years; range 42 to 80 years) with a diagnosis of MS according to the ATP III criteria. All patients underwent abdominal ultrasonography to detect NAFLD. Coronary angiography was performed for stable angina pectoris (n=48), unstable angina pectoris (n=21), and prognostic reasons (n=11). The severity of CAD was assessed by the number of vessels involved (vessel score) and the severity score (Gensini score). Significant stenosis was defined as 70% or greater reduction in lumenal diameter. Results: Ultrasonography revealed NAFLD in 43 patients (53.8%). Patients with NAFLD had significantly higher body mass index, waist circumference, and serum triglyceride level, and significantly lower HDL-cholesterol level (p<0.001). Coronary angiography showed significantly higher vessel (2.5 +/- 0.9 vs 1.0 +/- 1.0) and CAD severity scores (90.2 +/- 40.0 vs 36.4 +/- 28.9) in patients with NAFLD (p<0.001). Univariate analysis showed that the presence of NAFLD (r=0.61, p<0.001), grade of NAFLD (r=0.42, p<0.001), and patient age (r=0.36, p=0.002) were significantly correlated with the CAD severity score. In multivariate linear regression analysis, the presence of NAFLD was the only independent factor affecting the CAD severity score (beta: 1.35, p<0.001). Conclusion: The presence of NAFLD is associated with more severe CAD, requiring that patients with MS be investigated for the presence of NAFLD and those with NAFLD be attentively followed-up for the presence and severity of CAD.