BU Researchers Assemble Best Practice Advice for Diagnosing, Managing Nonalcoholic Fatty Liver Disease in Lean Individuals

Nonalcoholic fatty liver disease (NAFLD) is well recognized as a leading cause of chronic liver disease, affecting more than 25 percent of the U.S. and global population. One in four individuals with NAFLD have nonalcoholic steatohepatitis—a type of liver disease in which fat builds up in the liver of people who drink little or no alcohol, which is associated with significant morbidity and mortality due to complications of liver cirrhosis, hepatic decompensation (deterioration of liver function) and liver cancer.

Although NAFLD is observed predominantly in persons with obesity and/or type 2 diabetes mellitus (T2DM), an estimated seven to 20 percent of individuals with NAFLD have lean body build. Unfortunately, limited guidance has been available to clinicians on appropriate clinical evaluation in lean individuals with NAFLD until now.

Researchers have compiled a clinical practice update where they provide best practice advice on how to diagnose and manage nonalcoholic fatty liver disease among lean persons.

“This expert review was commissioned and approved by the American Gastroenterological Association (AGA) Institute Clinical Practice Updates Committee and the AGA Governing Board to provide timely guidance on a topic of high clinical importance to the AGA membership and underwent internal peer review by the Clinical Practice Updates Committee and external peer review,” said corresponding author Michelle T. Long MD, MSc, associate professor of gastroenterology at Boston University School of Medicine.

Among the 15 best practice advice statements are:

• Lean NAFLD should be diagnosed in individuals with NAFLD and a body mass index (BMI) < 25 kg/m2 (non-Asian race) or a BMI <23 kg/m2 (Asian race).
• Lean individuals with NAFLD should be evaluated for comorbid conditions, such as T2DM, dyslipidemia (elevated cholesterol) and hypertension.
• Lean individuals with NAFLD should be risk categorized for hepatic fibrosis (excessive connective tissue in the liver) to identify those with advanced fibrosis or cirrhosis.
• Lean individuals in the general population should not undergo routine screening for NAFLD; however, screening should be considered for individuals over the age of 40 with T2DM.

According to the researchers, it is difficult to identify those with NAFLD who are at the highest risk of disease progression. “About 10 percent of those with NAFLD are lean and traditionally this group has been even more difficult to diagnose as the condition often goes unrecognized,” explains Long who also is a gastroenterologist at Boston Medical Center.

These findings appear online in the journal Gastroenterology.