In this post, I link to and excerpt from Nonalcoholic Fatty Liver Disease and Cardiovascular Risk: A Scientific Statement From the American Heart Association [PubMed Abstract] [Full-Text PDF]. Originally published14 Apr 2022https://doi.org/10.1161/ATV.0000000000000153Arteriosclerosis, Thrombosis, and Vascular Biology. 2022;0:10.1161/ATV.0000000000000153
All that follows is from the above article.
Nonalcoholic fatty liver disease (NAFLD) is an increasingly common condition that is believed to affect >25% of adults worldwide. Unless specific testing is done to identify NAFLD, the condition is typically silent until advanced and potentially irreversible liver impairment occurs. For this reason, the majority of patients with NAFLD are unaware of having this serious condition. Hepatic complications from NAFLD include nonalcoholic steatohepatitis, hepatic cirrhosis, and hepatocellular carcinoma. In addition to these serious complications, NAFLD is a risk factor for atherosclerotic cardiovascular disease, which is the principal cause of death in patients with NAFLD. Accordingly, the purpose of this scientific statement is to review the underlying risk factors and pathophysiology of NAFLD, the associations with atherosclerotic cardiovascular disease, diagnostic and screening strategies, and potential interventions.
Keywords: AHA Scientific Statements; cardiovascular diseases; diabetes mellitus; hepatocytes; hypertriglyceridemia; insulin resistance; metabolic syndrome; nonalcoholic fatty liver disease; triglycerides.
In the United States, the prevalence of NAFLD varies by race and ethnicity. Hispanic individuals have the highest prevalence rates, followed by White and Black individu-als (21%, 12.5%, and 11.6%, respectively).3,4 Risk among Hispanic people is not uniformly distributed among sub-groups. For example, in MESA (Multi-Ethnic Study of Ath-erosclerosis), NAFLD prevalence among those of Mexican origin was 33%, but it was only 16% and 18% among those of Dominican and Puerto Rican origin, respectively.5
Accurate prevalence rates for NASH are difficult to approximate because diagnosis currently requires a liver biopsy for histology. In 1 study, among patients with NAFLD diagnosed by ultrasonography, biopsy-proven NASH was demonstrated in 19.4% of Hispanic and 9.8% of White patients (P=0.03).7 Among liver transplant donors, NASH prevalence rates vary from 1.4% to 15%.8–10 The estimated prevalence of NASH is 3% to 6%,11 with potentially higher rates among populations with the highest prevalence of NAFLD. Risk factors for NASH include type 2 diabetes, dyslipidemia, and obesity, all of which are prevalent. The prevalence of NASH in type 2 diabetes may exceed 37%.12 In a recently published study, 664 asymptomatic middle-aged American men and women with a mean body mass index (BMI) of 30.5 kg/m2 (15% with type 2 diabe-tes) referred for colonoscopy were assessed for hepatic steatosis and liver stiffness by magnetic resonance and ultrasound imaging. Patients with abnormal imaging param-eters were offered liver biopsy. The prevalence of NAFLD in this cohort was 38%, and biopsy-confirmed NASH was identified in 14%.13
The purpose of this scientific statement is to succinctly highlight the pathophysiology, association with CVD, diagnostic strategies, and potential interventions for NAFLD. An informational handout about NAFLD was also developed for patient education.TERMINOLOGY