Nonalcoholic Fatty Liver Disease: Common Questions and Answers on Diagnosis and Management
Am Fam Physician. 2020 Nov 15;102(9):603-612.
Related letter: NAFLD in Children and Adolescents
Related letter: Updated Statistics for Liver Biopsy Risk
Patient information: See related handout on nonalcoholic fatty liver disease, written by the authors of this article.
Author disclosure: No relevant financial affiliations.
- Who Is at Risk of NAFLD?
- Does Routine Screening of Asymptomatic Adults at Risk of NAFLD Improve Health?
- What Is the Characteristic Presentation of NAFLD?
- What Is Included in the Initial Evaluation of a Patient with Suspected NAFLD?
- When Should Liver Biopsy Be Considered in Patients with NAFLD?
- How Is NAFLD Treated?
- What Monitoring Is Recommended for NAFLD?
- What Is the Prognosis for Those with NAFLD?
- When Should Patients with NAFLD Be Referred to a Specialist?
Nonalcoholic fatty liver disease (NAFLD) is the most common form of liver disease in the United States, affecting up to 30% of adults. There are two forms of NAFLD: nonalcoholic fatty liver (NAFL), defined as 5% or greater hepatic steatosis without hepatocellular injury or fibrosis, and nonalcoholic steatohepatitis (NASH), defined as 5% or greater hepatic steatosis plus hepatocellular injury and inflammation, with or without fibrosis. Individuals with obesity are at highest risk of NAFLD. Other established risk factors include metabolic syndrome and type 2 diabetes mellitus. Although NAFLD is common and typically asymptomatic, screening is not currently recommended, even in high-risk patients. NAFLD should be suspected in patients with elevated liver enzymes or hepatic steatosis on abdominal imaging that are found incidentally. Once other causes, such as excessive alcohol use and hepatotoxic medications, are excluded in these patients, risk scores or elastography tests can be used to identify those who are likely to have fibrosis that will progress to cirrhosis. Liver biopsy should be considered for patients at increased risk of fibrosis and when other liver disorders cannot be excluded with noninvasive tests. Weight loss through diet and exercise is the primary treatment for NAFLD. Other treatments, such as bariatric surgery, vitamin E supplements, and pharmacologic therapy with thiazolidinediones or glucagon-like peptide-1 analogues, have shown potential benefit; however, data are limited, and these therapies are not considered routine treatments. NAFL typically follows an indolent course, whereas patients with NASH are at higher risk of death from cardiovascular disease, cancer, and end-stage liver disease.
Nonalcoholic fatty liver disease (NAFLD) comprises a continuum of fatty liver disease that occurs in the absence of alcohol use or other secondary causes of hepatic steatosis. There are two manifestations of NAFLD (Figure 1).1 One is nonalcoholic fatty liver (NAFL), which is defined as 5% or greater hepatic steatosis without evidence of hepatocellular injury or fibrosis. The other is nonalcoholic steatohepatitis (NASH), which is defined as 5% or greater hepatic steatosis with hepatocellular injury and inflammation, with or without fibrosis.1
WHAT'S NEW ON THIS TOPIC
It is projected that 100 million people in the United States will have nonalcoholic fatty liver disease by 2030, with direct medical costs of about $103 billion annually.
By 2030, nonalcoholic steatohepatitis is predicted to become the leading indication for liver transplantation in U.S. adults, surpassing hepatitis C.
SORT: KEY RECOMMENDATIONS FOR PRACTICE
NAFLD = nonalcoholic fatty liver disease.
A = consistent, good-quality patient-oriented evidence; B = inconsistent or limited-quality patient-oriented evidence; C =
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