New research to be presented at Digestive Disease Week® (DDW) 2022 suggests that patients with normal body mass index (BMI) with non-alcoholic fatty liver disease (NAFLD) are more likely to have cardiovascular disease (CVD) than those with NAFLD who are overweight or living with obesity.
“It seems counterintuitive that those with a normal BMI would have a higher prevalence of cardiovascular disease, but our research highlighted this connection,” said Dr. Karn Wijarnpreecha, lead researcher of the study and transplant hepatology fellow at the University of Michigan. “This finding could have significant implications on patient care and warrants further analysis.”
The retrospective cohort study looked at more than 10,000 adults with NAFLD at the University of Michigan from 2012 to 2021. Researchers divided the patients into lean, overweight, class 1 obesity and class 2-3 obesity based on their BMI and looked at the prevalence of cirrhosis, CVD, metabolic diseases and chronic kidney disease in the various groups.
The results showed that, compared to NAFLD patients who were overweight or living with obesity, lean NAFLD patients consistently had a higher rate of CVD — including coronary artery disease, peripheral arterial disease, cerebrovascular disease and congestive heart failure. Somewhat paradoxically, these patients had a significantly higher rate of CVD even though they had a lower prevalence of risk factors associated with CVD, such as diabetes, hypertension and dyslipidemia.
Dr. Wijarnpreecha stressed that it is too early to draw any conclusions regarding whether normal BMI in NAFLD patients increases the risk of developing CVD. Future prospective studies should help shed light on the risk and incidence of comorbid conditions in NAFLD patients and how it relates to BMI.
“We cannot definitively state that lean NAFLD patients have a higher risk of cardiovascular disease. The only conclusion we can draw from this study is that there was a higher prevalence of CVD in the lean group than in the overweight or obese NAFLD groups. Whether lean NAFLD patients are going to develop CVD or have a higher risk requires additional research,” said Dr. Wijarnpreecha.
Despite these caveats, the study does offer clinicians a reason to think twice when assessing their lean NAFLD patients and not to presume a patient’s cardiovascular health based on their weight, he said.
“Right now we tend to focus on NAFLD patients who are overweight or those living with obesity because we see this a lot in the clinic,” said Dr. Wijarnpreecha. “However, I would say that NAFLD patients with a normal BMI should not be overlooked in clinical practice. Even though they have a normal BMI, it doesn’t mean they don’t have a high risk of cardiovascular disease.”
Dr. Wijarnpreecha will present data from the study, “Higher prevalence of cardiovascular disease among lean versus non-lean patients with nonalcoholic fatty liver disease despite lower prevalence of atherogenic risk and metabolic diseases,” abstract 325, on Sunday, May 22, at 8:30 a.m. PDT.