NAFLD tied to CVD risk even in lean patients

Individuals with nonalcoholic fatty liver disease (NAFLD) –  despite having a lean body or healthy BMI – are at an elevated risk for peripheral vascular disease, stroke, and cardiovascular disease (CVD), a finding that surprises gastroenterologists and researchers at DDW 2022.

“We were surprised to find there’s a CVD  link,” said lead researcher Dr Karn Wijarnpreecha, a gastroenterologist at the University of Michigan in Ann Arbor, Michigan, US. “We would have expected a lower prevalence of metabolic and cardiovascular conditions in those with a normal BMI, but we were wrong all along.”

Using data from 18,793 adults diagnosed with NAFLD at the University of Michigan Hospital in a span of almost 9 years, Wijarnpreecha and his team sought to compare the prevalence of cirrhosis, CVD, metabolic diseases, and chronic kidney disease (CKD) in this cohort in relation to their BMI. [DDW 2022, abstract 325]

Individuals were classified into lean, overweight, obese class 1, and obese class 2–3 based on their BMI.

Higher rates of PAD and stroke

Contrary to expectations, lean patients with NAFLD had a higher prevalence of peripheral arterial disease (PAD) and stroke than non-lean patients. The rates of CVD were similar between groups. Nealy 6 percent of the lean patients had PAD vs 4–5 percent in overweight and obese individuals.

“Lean patients with NAFLD also had a significantly higher prevalence of CVD, independent of age, sex, race, smoking status, diabetes, hypertension, and dyslipidaemia,” Wijarnpreecha reported.

Compared with non-lean patients, lean patients had a lower prevalence of cirrhosis, diabetes, hypertension, dyslipidaemia, and CKD after adjustment for confounders.

The findings suggest that clinicians should consider CVD risk in all patients with NAFLD, without regard for obesity status, said Wijarnpreecha.

Early-stage NAFLD does not usually cause any harm, but it can lead to serious liver damage, including cirrhosis, if not treated. A wide range of conditions can increase the risk, including diabetes, high cholesterol, and obesity.

More research warranted

When asked what was causing the increased CVD risk in otherwise lean and healthy NAFLD patients, Wijarnpreecha said it could be the difference in lifestyle, diet, exercise, genetics, or even gut microbiota. However, the study wasn’t designed to capture those variables.

“Hence, we need further studies to fully understand what the findings mean, and what the therapeutic implications might be,” commented Dr Arun Sanyal, director of the Stravitz-Sanyal Institute for Liver Disease & Metabolic Health, Virginia Commonwealth University in Richmond, Virginia, US.

Wijarnpreecha’s team is now planning to conduct more research to dig deeper into NAFLD and CVD risk in lean patients.