Nonalcoholic Fatty Liver Disease: An Emerging Modern-Day Risk Factor for Cardiovascular Disease

Nonalcoholic fatty liver disease (NAFLD), also named metabolic dysfunction-associated fatty liver disease (MAFLD), is a progressive disease spectrum encompassing simple steatosis, nonalcoholic steatohepatitis (NASH), fibrosis, and cirrhosis. It is a clinically silent disease leading to multiple extra-hepatic complications/comorbidities. It is an independent risk factor for cardiovascular disease (CVD), increasing susceptibility to hypertension, atherosclerosis, arrhythmia, myocardial dysfunction, cardiac valve deformation, and venous thrombosis through putative mechanisms including systemic inflammation, endothelial dysfunction, oxidative stress, insulin resistance, and altered lipid metabolism. Eventually, it increases the CVD prevalence, incident, and fatality, contributing to a huge health care burden. In fact, CVD is becoming the leading cause of mortality among patients with NAFLD. Other cardiometabolic risk factors coexisting with NAFLD may also accelerate the synergistic development of CVD, which warrants assessment targeting hypertension, diabetes mellitus (DM), obesity, and dyslipidemia to be an integral part of NAFLD care. Monitoring metabolic biomarkers (glucose, glycosylated hemoglobin [HbA1c], insulin, lipids, and lipoproteins), cardiovascular (CV) risk scores ( American College of Cardiology/American Heart Association [ACC/AHA] or Framingham), and subclinical atherosclerosis (coronary artery calcification [CAC], carotid intima- media thickness [CIMT], and carotid plaque) are recommended for risk prediction and reduction. There is no universally accepted treatment for NAFLD, and lifestyle changes with weight loss of at least 10% are the mainstay of management. Combination therapy of ezetimibe and statins have a cardioprotective effect and help reduce liver fat. Despite being an emerging risk factor for CVD and its rapidly increasing pattern affecting a quarter of the global population, NAFLD remains overlooked and undetected, unlike the other traditional risk factors. Hence, we conducted a comprehensive narrative review to shed more light on the importance of screening CVD in NAFLD patients. PubMed indexed relevant articles published from 2002 to 2022 (20 years) were searched in April 2022 using medical subject headings (MeSH) as "nonalcoholic fatty liver disease" [Mesh] AND "cardiovascular diseases" [Mesh]. Evidence from 40 observational studies, three clinical trials, one case series, 45 narrative reviews, four systematic reviews and meta-analyses, three systematic reviews, and one meta- analysis were summarized on the epidemiologic data, pathophysiologic mechanisms, clinical features, diagnostic modalities, overlapping management, perceived challenges and health literacy regarding the CVD risk attributed to NAFLD.