Non-alcoholic fatty liver disease is strongly associated with carotid atherosclerosis: A systematic review

Background/Aims To perform a systematic review of the studies addressing the association between non-alcoholic fatty liver disease (NAFLD) and carotid intima-media thickness (IMT). Methods Literature searches identified seven studies that met inclusion criteria: population-based or hospital-based case-control studies about the relation between NAFLD and carotid IMT, in which information on number of subjects in controls and NAFLD patients, and data to evaluate carotid IMT and carotid plaques (measured by carotid ultrasound) could be extracted. Results From a total of 3497 subjects (1427 patients and 2070 controls), we found a significant association between NAFLD and carotid IMT either in fixed (D: 0.51, 95% CI: 0.44–0.58, p < 1 × 10−8) or random models (D: 1.44, CI: 95% 0.63–2.24, p < 0.0006). Meta-regression analysis showed that mean differences in alanine aminotransferase and γ-GT were strongly correlated with those in IMT (p < 0.00006 and 0.004, respectively). In addition, 5 reports including 3212 subjects showed that carotid plaques were more frequently observed in NAFLD patients in comparison with controls, fixed model (p < 1 × 10−10), OR: 1.97 95% CI: 1.67–2.32 and random model p < 0.0002, OR: 3.13, 95% CI: 1.75–5.58. Conclusions Routine measurement of carotid IMT might be implemented in NAFLD patients, as they carry an increase of 13% of carotid IMT.