People with increased intermuscular fat are more likely to die or be hospitalized from a heart attack or heart failure, regardless of their body mass index.
- Intermuscular fat reflects muscle quality and is associated with inflammation, a key factor in cardiometabolic disease.
- “For every 1% increase in muscle fat fraction, the risk of coronary microvascular dysfunction increased by 2% and the risk of future serious heart disease increased by 7%, regardless of other known risk factors and mass index. bodily.”
- On the other hand, an increase in subcutaneous fat, that is, that stored under the skin, did not increase the risk.
“Intermuscular fat is found in most muscles in the body, but the amount of fat can vary greatly from person to person,” said scientists from Brigham and Women’s Hospital (United States). In a recent study, they wanted to analyze muscles and different types of fat to understand how body composition can influence the small blood vessels or “microcirculation” of the heart, as well as the future risk of heart failure, heart attack and death.
Chest pain, shortness of breath: 669 patients followed for 6 years
For research purposes, 669 people, aged 63 on average, were recruited. They had chest pain and/or shortness of breath, but showed no signs of obstructive coronary artery disease, which is when the arteries that supply the heart are dangerously blocked. Participants were followed for six years for major adverse cardiovascular events, including death and hospitalization for myocardial infarction or heart failure.
During the procedure, they all underwent cardiac positron emission tomography/computed tomography (PET/CT) scans to assess how their hearts were functioning. The researchers also used CT scanning to analyze each adult’s body composition, measuring the amount and location of fat and muscle in a section of their torso. To quantify the amount of fat stored in muscle, they calculated the ratio of intermuscular fat to total muscle and fat, a measure they called “muscle fat fraction.”
Fat accumulation in muscles linked to risk of coronary microvascular dysfunction
Volunteers with higher amounts of fat stored in their muscles were more likely to suffer from coronary microvascular dysfunction (CMD), which is damage to the tiny blood vessels that serve the heart, and that they were more likely to die or be hospitalized for heart disease. “For every 1% increase in muscle fat fraction, the risk of CMD increased by 2% and the risk of future serious heart disease increased by 7%, regardless of other known risk factors and body mass index.” , can we read in the results published in the journal European Heart Journal.
Adults who had high levels of intermuscular fat and signs of coronary microvascular dysfunction were at particularly high risk of death, heart attack, and heart failure. In contrast, people with higher amounts of lean muscle had a lower risk. Subcutaneous fat, that is, that stored under the skin, did not increase the risk.
“Fat stored in muscles can contribute to inflammation”
“Compared to subcutaneous fat, fat stored in muscle can contribute to inflammation and impaired glucose metabolism, leading to insulin resistance and metabolic syndrome. In turn, these insults Chronic conditions can damage blood vessels, including those that supply the heart, and the heart muscle itself Knowing that intermuscular fat increases the risk of heart disease gives us another way to identify people at high risk. , whatever their index “These findings may be particularly important for understanding the effects of fat- and muscle-modifying incretin therapies on heart health, including the new class of glucagon-like peptide-1 receptor agonists.” declared Viviany Taquetiwho led the research.
