New study surprises researchers who say doctors may miss thin patients with non-alcoholic fatty liver disease
People with a normal body mass index (BMI) with nonalcoholic fatty liver disease (NAFLD) are more likely to have cardiovascular disease than those who are overweight or living with obesity, according to research selected for their presentation at Digestive Disease Week® (DDW ) 2022. About 25 percent of adults in the US have NAFLD, a term for several liver conditions that affect those who drink little or no alcohol.
This link to cardiovascular disease was found even though lean patients were less likely to have cirrhosis, diabetes, high cholesterol, or high blood pressure.
"Our team expected to see that those with a normal BMI would have a lower prevalence of any metabolic or cardiovascular conditions, so we were very surprised to find this link with cardiovascular disease," said Karn Wijarnpreecha, MD, MPH, principal investigator of the study and transplantation of hepatology at the University of Michigan. “Too often, we overlook NAFLD patients with a normal BMI because we assume their risk for more serious conditions is lower than those who are overweight. But this way of thinking may be putting these patients at risk.”
The main characteristic of NAFLD is having too much fat stored in the liver cells. It usually has no symptoms and can lead to other dangerous conditions, such as diabetes, cardiovascular disease, and liver cirrhosis.
While NAFLD is more common in people who are overweight or living with obesity, it is also found in people who have a normal BMI. However, there is little to no research conducted on the associated conditions of this population in relation to the condition.
Researchers conducted a retrospective cohort study of more than 10,000 adults diagnosed with NAFLD at the University of Michigan Hospital between 2012 and 2021 to compare the prevalence of cirrhosis, cardiovascular disease, metabolic diseases, and chronic kidney disease among four classes of patients. : thin (BMI = 18.5 to 24.9), overweight (BMI = 25-29.9), obesity class 1 (BMI = 30-34.9) and obesity class 2-3 (BMI = 35-<40 ).
They found that compared with non-lean patients, lean patients had a lower prevalence of cirrhosis, diabetes mellitus, hypertension, and dyslipidemia; but a higher prevalence of peripheral vascular disease, cerebrovascular disease and any cardiovascular disease.
"In further analysis, we found that lean patients with NAFLD also had a significantly higher prevalence of cardiovascular disease, independent of age, sex, race, smoking, diabetes, hypertension, and dyslipidemia," said Dr. Wijarnpreecha.
The researchers plan to conduct additional studies that will follow patients long-term to determine whether lean patients are at increased risk of developing cardiovascular disease as a result of NAFLD.
Given the unknown reasons behind the higher prevalence of cardiovascular disease among lean patients with NAFLD, researchers encourage clinicians not to overlook lean patients with NAFLD, as they may face serious health consequences similar to patients overweight or living with obesity.
