Persistent Nonalcoholic Fatty Liver Disease Increases Risk for Carotid Atherosclerosis

Background & aims: Nonalcoholic fatty liver disease (NAFLD) has been associated with subclinical atherosclerosis in cross-sectional studies. We investigated the longitudinal association of NAFLD with the development of subclinical carotid atherosclerosis.

Methods: We performed a retrospective cohort study of 8020 adult men (average age, 49.2 y) without carotid atherosclerosis at baseline who underwent repeated health check-up examinations from January 1, 2005, through December 31, 2013. NAFLD status was diagnosed by ultrasonography and classified into 4 groups based on baseline and follow-up findings: none, developed, regressed, or persistent NAFLD. Subclinical carotid atherosclerosis was measured by ultrasound.

Results: The age-adjusted hazard ratio for subclinical carotid atherosclerosis development comparing participants with persistent NAFLD with those without NAFLD was 1.23 (95% confidence interval [CI], 1.13-1.35; P < .001). The association persisted after adjustment for smoking, alcohol, body mass index, and weight change (hazard ratio, 1.13; 95% CI, 1.03-1.25; P = .014), but disappeared after adjustment for metabolic variables. The hazard ratio, comparing subjects with regression of NAFLD vs those with persistent NAFLD, was 0.82 (95% CI, 0.69-0.96; P = .013). The risk of subclinical carotid atherosclerosis development also was higher among participants with a high NAFLD fibrosis score, fibrosis-4 scores, or levels of γ-glutamyl transferase at baseline.

Conclusions: In a large cohort study, persistent NAFLD was associated with an increased risk of subclinical carotid atherosclerosis development. This association was explained by metabolic factors that could be potential mediators of the effect of NAFLD. Markers of liver fibrosis also were associated with subclinical carotid atherosclerosis development. Prospective studies are needed to determine whether treatment of NAFLD can reduce this risk.