At least one in four adults worldwide is thought to have nonalcoholic fatty liver disease, a major risk factor for cardiovascular disease (CVD), which is the leading cause of death in NAFLD, but the condition is widely underdiagnosed, according to a new American Heart Association scientific statement on NAFLD and cardiovascular risks.
The statement,in Arteriosclerosis, Thrombosis, and Vascular Biology, aims to increase awareness of NAFLD among cardiologists and other clinicians treating vulnerable patients. It pulls together the existing evidence for using imaging to diagnose NAFLD as well as the role of current and emerging treatments for managing the disease.
“NAFLD is common, but most patients are undiagnosed,” statement writing committee chair P. Barton Duell, MD, said in an interview. “The identification of normal liver enzyme levels does not exclude the diagnosis of NAFLD. Early diagnosis and treatment are necessary to improve the health of patients with established NAFLD, as well as preventing the development of NAFLD in patients who are at risk for the condition.”
Dr. Duell is a professor at the Knight Cardiovascular Institute and division of endocrinology, diabetes and clinical nutrition at Oregon Health & Science University, Portland.
This is the AHA’s first scientific statement on NAFLD. In 2021, the association issued aon obesity and CVD). Also in 2021, a multiorganization group headed by the American Gastroenterological Association a “Call to Action” on nonalcoholic steatohepatitis (NASH) , a form of NAFLD that’s characterized by inflammation and scarring of the liver, and typically requires a liver biopsy for diagnosis.
The AHA statement on NAFLD is sweeping. Among its key take-home messages:
- Calling into question the effectiveness of AST and ALT testing for diagnosing NAFLD and NASH.
- Providing context to the role of insulin resistance – either with or without diabetes – as well as obesity (particularly visceral adiposity), metabolic syndrome, and dyslipidemia in NAFLD.
- Advocating for lifestyle interventions – diet, exercise, weight loss and alcohol avoidance – as the key therapeutic intervention for NAFLD.
- Asserting that glucagonlike peptide–1 receptor agonists may modestly improve NAFLD.
The statement also tackles the differences in terminology different organizations use to describe NAFLD. “The terminology section is important to ensure everyone is using the right terminology in assessing patients, as well as choosing appropriate treatment interventions,” Dr. Duell said.
The statement also explores genetic factors that can predispose people to NAFLD, Dr. Duell pointed out, and it goes into detail about strategies for screening NAFLD and NASH. “It is not possible to diagnose NAFLD without understanding the pros and cons of various screening modalities, as well as the lack of sensitivity of some tests for detection of NAFLD We hope this information will increase success in screening for and early identification of NAFLD.”
Dr. Duell explained the rationale for issuing the statement. “Rates of NAFLD are increasing worldwide in association with rising rates of elevated body mass index and the metabolic syndrome, but the condition is commonly undiagnosed,” he said. “This allows patients to experience progression of disease, leading to hepatic and cardiovascular complications.”
Avoiding NAFLD risk factors along with early diagnosis and treatment “may have the potential to mitigate long-term complications from NAFLD,” Dr. Duell said.
“This is one of first times where we really look at cardiovascular risks associated with NAFLD and pinpoint the risk factors, the imaging tools that can be used for diagnosing fatty liver disease, and ultimately what potential treatments we can consider,” Tiffany M. Powell-Wiley, MD, MPH, author of the AHA statement on obesity and CV risk, said in an interview.
“NAFLD has not been at the forefront of cardiologists’ minds, but this statement highlights the importance of liver fat as a fat depot,” said Dr. Powell-Wiley, chief of the Social Determinants of Obesity and Cardiovascular Risk Laboratory at the National Heart, Lung, and Blood Institute in Bethesda, Md.
“It does provide greater clarity for us as cardiologists, especially when thinking about what is required for diagnosis and ultimately how this relates to cardiovascular disease for people with fatty liver disease,” she said.
Dr. Duell and Dr. Powell-Wiley have no relevant relationships to disclose.