Non-alcoholic fatty liver disease (NAFLD) and its association to cardiovascular disease: A comprehensive meta-analysis

Background Non-alcoholic fatty liver disease (NAFLD) affects up to nearly a third of the Western population and has been inconsistently associated with cardiovascular diseases (CVDs). Therefore, we conducted a comprehensive meta-analysis to quantify the correlation of NAFLD with all major vascular diseases, acute coronary syndrome (ACS), subclinical atherosclerosis and endothelial dysfunction. Methods We searched PubMed and Embase for studies looking at the relationship between NAFLD and cardiovascular diseases published through September 2023. The parameters we used to assess cardiovascular diseases include acute coronary syndrome, brachial flow-mediated dilatation (FMD), serum asymmetric dimethylarginine (ADMA), carotid intima-media thickness (CIMT), and carotid stenosis (>50%). Data from these studies were then collected and meta-analysis was performed using the random effects model. RevMan v5.4 was used for statistical analysis. Results We interrogated a total of 114 publications which met our inclusion criteria. NAFLD patients showed statistically significant reduction in FMD% [MD: −4.83 (95% CI: −5.84 to 3.81, p < .00001)] and increased serum ADMA [MD: 0.08 (95% CI: 0.05–0.11, p < .00001)]. Mean CIMT was also increased in NAFLD patients [MD 0.13 (95% CI: 0.12–0.14, p < .00001)]. NAFLD showed a higher prevalence of pathological CIMT [MD: 0.11 (95% CI: 0.10–0.12, p < .00001)] and increased carotid plaques [OR: 2.08 (95% CI: 1.52–2.86, p < .00001)]. Furthermore, we demonstrated statistically significant increase in cardiovascular diseases among NAFLD patients compared to controls [OR: 1.92 (95% CI: 1.53–2.41, p < .00001)]. Conclusion NAFLD is a strong predictor for endothelial dysfunction, subclinical atherosclerosis and cardiovascular disease. Further studies are required to determine whether incidental findings of fatty liver on abdominal ultrasonography should prompt the need for detailed assessment of other CVD risk factors.