Hidden muscle fat, not BMI, linked to heart risks: Study finds
New research published in the "European Heart Journal" indicates that individuals with a more significant amount of fat hidden within their muscles are more susceptible to hospitalization or death due to heart attack and heart failure. According to scientists, body mass index (BMI) is irrelevant.
The latest studies published in the European Heart Journal suggest that intramuscular fat can significantly increase the risk of heart disease, regardless of body mass index (BMI). A research team led by Prof. Viviana Taqueti from Brigham and Women's Hospital and Harvard Medical School conducted studies that shed new light on the impact of intramuscular fat on heart health.
Intramuscular fat and heart health
Intramuscular fat is mainly known from gastronomy—famous Japanese Wagyu beef owes its valued "marbling" to connoisseurs. Farmers achieve it by ensuring the cows live stress-free lives, comfortable "living" conditions, plenty of food, little effort, and even relaxing massages. Unfortunately, in humans, intramuscular fat can lead to serious health issues.
Studies have shown that individuals with more fat in their muscles are more prone to damage to the small blood vessels of the heart, which increases the risk of heart attack and heart failure.
Intermuscular fat can be found in most muscles in the body, but the amount of fat can vary widely between different people. In our research, we analyse muscle and different types of fat to understand how body composition can influence the small blood vessels or ‘microcirculation’ of the heart, as well as future risk of heart failure, heart attack and death," emphasized Prof. Taqueti.
The study involved 669 Brigham and Women's Hospital patients diagnosed with chest pain and shortness of breath. The average age of participants was 63, and most were women. The research found that for every 1% increase in muscle fat fraction, the risk of CMD increased by 2%, and the risk of severe heart disease increased by 7%, regardless of other known risk factors and BMI.
Individuals with high levels of intramuscular fat and evidence of CMD were particularly at risk of death, heart attack, and heart failure.
scientists say BMI doesn't matter here
Prof. Taqueti emphasizes that intramuscular fat can contribute to inflammation and glucose metabolism disorders, leading to insulin resistance and metabolic syndrome. These chronic damages can affect the heart's blood vessels. Knowledge of the impact of intramuscular fat on heart health can help identify high-risk individuals, regardless of their BMI.
The research suggests that individuals with a higher percentage of lean muscle mass have a lower risk of heart disease. Subcutaneous fat does not increase this risk. Prof. Taqueti and her team are investigating the impact of various treatment strategies on body composition and heart health, such as exercise, diet, or weight-loss drugs.
These findings can be crucial for understanding the impact of new therapies on heart health, yet it is still unknown how to effectively reduce risk in individuals with fatty muscles. Research on this issue is ongoing.
