Fatty Muscles & Heart Disease Risk | Weight Doesn’t Matter
Fat within your muscles, not overall weight, poses a important threat to your heart health. A new study reveals that intermuscular fat independently increases the risk of heart attack and heart failure, irrespective of your body mass index (BMI). Researchers found a strong link between higher intermuscular fat and coronary microvascular dysfunction (CMD), potentially leading to serious heart disease. Conversely, increased lean muscle mass helps lower these risks. This groundbreaking research, published in the European Heart Journal, underscores the limitations of BMI and highlights the importance of considering body composition. News Directory 3 explores this critical information, offering insights into how this hidden fat impacts your cardiovascular system. Discover what’s next regarding strategies to mitigate fatty muscle risks.
Hidden Muscle Fat Tied to Increased Heart attack Risk
Updated June 15, 2025
Boston — Fat lurking within muscles, known as intermuscular fat, elevates the risk of heart attack and heart failure, nonetheless of body mass index, according to a new study. The research, published in the European Heart Journal, highlights the inadequacy of BMI as a sole indicator of cardiovascular health.
The study, led by Professor Viviany Taqueti at Brigham and Women’s Hospital and Harvard Medical School, involved 669 patients evaluated for chest pain or shortness of breath who showed no signs of blocked arteries. The average age was 63; 70% were women and 46% were non-white. Cardiac PET/CT scans assessed heart function, while CT scans measured fat and muscle distribution in the torso.
Researchers calculated the “fatty muscle fraction” to quantify fat within muscles. Over six years, they tracked deaths and hospitalizations for heart issues. Results showed that higher intermuscular fat correlated with damage to small heart blood vessels, known as coronary microvascular dysfunction (CMD), and increased the likelihood of death or hospitalization for heart disease. A 1% rise in fatty muscle fraction led to a 2% greater CMD risk and a 7% higher risk of serious heart disease.
Those with both high intermuscular fat and CMD faced the greatest risk. Conversely, higher lean muscle mass reduced risk. Subcutaneous fat, located under the skin, did not increase risk.
Taqueti suggests intermuscular fat may trigger inflammation and disrupt glucose metabolism, leading to insulin resistance and metabolic syndrome, which damages blood vessels and the heart. ”Knowing that intermuscular fat raises the risk of heart disease gives us another way to identify people who are at high risk, regardless of their body mass index,” Taqueti said.
The research team is now studying how exercise,diet,weight-loss drugs,and surgery affect body composition and metabolic heart disease.
What’s next
Future research will focus on strategies to reduce the risk associated with fatty muscles, including the impact of weight-loss therapies on muscle fat and heart health.