Muscle Fat Can Be Deadlier Than A Pot Belly

Myosteatosis is generally found in those who are already sick and undergoing medical imaging for another illness, and it can lead to serious health problems which include heart attacks and strokes. However, myosteatosis can often have no symptoms, the researchers hope that their findings may help open new paths for the development of screening programs and personalized treatments for those who are most at risk. 

“To date, medical imaging with CT or MRI remains the gold standard to evaluate myosteatosis,” said study co-author Maxime Nachit, M.D., Ph.D., a post-doctoral researcher at the Institut de Recherche Expérimentale et Clinique at UCLouvain in Brussels, Belgium. 

The team utilized artificial intelligence and deep machine learning that was developed in the laboratory of co-author Ronald M. Summers, M.D., Ph.D., at the National Institutes of Health Clinical Center to extract participant body composition metrics from abdominal CT scans of asymptomatic adults who underwent routine bowel screenings. 

Findings from this retrospective study involving 8,982 adults found a 10-year mortality risk of 15.5% for those with myosteatosis compared to a mortality rate of 7.6% for those with obesity, 8.6% for those with liver steatosis, and 9.7% for those with myopenia. Over an average follow-up period of 8.8 years, 507 participants died. 

The presence of other health factors such as visceral fat or liver steatosis were also associated with an increased mortality risk, but myosteatosis remained the highest risk, being comparable to the mortality risks associated with smoking or having type 2 diabetes. 

“Interestingly, the relationship was independent from age or markers of obesity such as BMI,” Dr. Nachit said. “This suggests that muscle fat accumulation is not simply a result of aging or having excessive fat in other body areas.” “In other words, this means that fat accumulation in the muscles is not merely explained by being older and/or having fat overload in other locations of the body.”

“We are witnessing the onset of ‘personalized medicine,’ whose aim is to tailor medical management at the individual level based on a constellation of information such as genetics, medical history, physical characteristics, complex and large-scale molecular evaluation, etc.,” Dr. Nachit said. “Here, we show that myosteatosis – a parameter retrievable from medical images performed routinely in hospitals – is a robust indicator of an individual’s mortality risk at a relatively short term.”