BMI and waist circumference are not only risk factors for heart disease. This hidden fat may be more important

For years, health experts have debated whether body mass index (BMI) is the best measure of a person’s health. Although waist circumference has been considered a key predictor of heart disease, a recent study shows that neither BMI nor waist measurement is a definitive predictor.

Instead, a hidden factor, intermuscular fat, the fat stored in muscles, may be a more accurate indicator of heart disease risk. The researchers noted that people with higher amounts of this particular type of fat were at greater risk of death and hospitalization from a heart attack or heart failure, regardless of BMI or waist circumference.

“Obesity is currently one of the world’s greatest threats to cardiovascular health, yet body mass index – our main indicator of obesity and intervention thresholds – remains a controversial and erroneous indicator of cardiovascular prognosis. This is particularly true for women whose high body mass index may reflect more ‘benign’ types of fat,” said Professor Viviana Taqueti, who led the study, in her speech. press release.

The study looked at how different compositions of muscle and fat affect the small blood vessels, or “microcirculation,” of the heart and influence the risk of developing heart failure, heart attack and death.

The study included 669 Brigham and Women’s Hospital patients, mean age 63, who had been diagnosed with chest pain or shortness of breath but had no symptoms of obstructive coronary artery disease.

The patients underwent cardiac PET/CT to assess cardiac function and computed tomography to analyze body composition, including the distribution of fat and muscle tissue in the trunk. Scientists have introduced a new measurement called muscle fat fraction, which quantifies the ratio of intermuscular fat to total muscle and fat.

Participants were followed for about six years to check outcomes, including hospitalization and death from heart attack or heart failure.

The analysis found that higher levels of muscle fat fraction were associated with a 2% greater risk of coronary microvascular dysfunction (CMD) and a 7% greater risk of future major heart disease for every 1% increase in muscle fat fraction, regardless of other factors. risk factors and BMI.

“Compared to subcutaneous fat, fat stored in muscle can contribute to inflammation and changes in glucose metabolism, leading to insulin resistance and metabolic syndrome. In turn, this chronic damage can cause damage to blood vessels, including those supplying the heart, and the heart of the muscle itself,” explained Professor Taqueti.