Relationship between Nonalcoholic Fatty Liver Disease and Carotid Artery Atherosclerosis Beyond Metabolic Disorders in Non-Diabetic Patients

BACKGROUND: The objective of this study was to investigate the association between nonalcoholic fatty liver disease (NAFLD) and carotid artery atherosclerosis beyond metabolic disorders. METHODS: We studied 320 non-diabetic patients with ultrasonographically diagnosed NAFLD and 313 non-diabetic patients without NAFLD who have less than 40 g alcohol/week drinking history. Carotid atherosclerotic burden was assessed by carotid intima-media thickness (IMT) and plaque. All subjects were divided to the metabolic syndrome (MetS) according to International Diabetes Federation criteria. RESULTS: NAFLD patients had a significantly increased mean carotid IMT (0.79 ± 0.18 vs. 0.73 ± 0.13 mm; p < 0.001) than those without the condition. The prevalence of increased IMT, defined as IMT ≥ 1 mm, and carotid plaque were 52.5% and 34.1% in the patients with NAFLD vs. 35.8% and 18.8% in the patients without this condition (p < 0.001). The difference in IMT and prevalence of plaque was also significant even in patients without MetS as well as those with MetS (all p < 0.05). NAFLD-associated adjusted odds ratio for increased IMT was 1.236 [95% confidence interval (CI), 1.023-1.467, p = 0.016] without MetS and 1.178 (95% CI, 1.059-1.311, p = 0.003) with MetS. NAFLD-associated adjusted odds ratio of carotid plaque was 1.583 (95% CI, 1.309-1.857, p = 0.024) without MetS and 1.536 (95% CI, 0.512-4.604, p = 0.444) with MetS. CONCLUSION: NAFLD is significantly associated with carotid atherosclerosis in non-diabetic outpatients even without MetS. Carotid screening for NAFLD might be beneficial for assessment of future atherosclerotic complications.