n### Hidden Fat in Muscles Linked to Higher Heart Disease Risk, Study Finds
A groundbreaking study published in the European Heart Journal reveals that hidden pockets of fat within muscles, known as intermuscular fat, substantially increase the risk of heart attack, heart failure, and death. This discovery challenges the adequacy of traditional measures like body mass index (BMI) and waist circumference in assessing cardiovascular risk.Led by Professor Viviany Taqueti, Director of the Cardiac Stress Laboratory at Brigham and Women’s Hospital and Faculty at Harvard Medical School, the research highlights how intermuscular fat impacts the microcirculation of the heart. “obesity is now one of the biggest global threats to cardiovascular health, yet body mass index – our main metric for defining obesity and thresholds for intervention – remains a controversial and flawed marker of cardiovascular prognosis,” said Taqueti. “This is especially true in women, where high body mass index may reflect more ‘benign’ types of fat.”
The study involved 669 patients, predominantly female (70%) and nearly half non-white (46%), who were evaluated for chest pain or shortness of breath but showed no signs of obstructive coronary artery disease. Using cardiac PET/CT scans, researchers analyzed body composition, focusing on the ratio of intermuscular fat to total muscle and fat, termed the fatty muscle fraction.
Over a six-year follow-up, the findings were striking. For every 1% increase in fatty muscle fraction,there was a 2% rise in the risk of coronary microvascular dysfunction (CMD) and a 7% increase in the likelihood of severe heart disease. Patients with high intermuscular fat and CMD faced the highest risks of death, heart attack, and heart failure. In contrast, those with more lean muscle had a lower risk, while subcutaneous fat (fat under the skin) showed no notable impact.”Compared to subcutaneous fat, fat stored in muscles may be contributing to inflammation and altered glucose metabolism leading to insulin resistance and metabolic syndrome,” the study noted. These chronic conditions can damage blood vessels and the heart muscle itself.
This research underscores the need for more precise tools to assess heart disease risk, particularly for individuals who may not fit traditional obesity metrics. It also opens new avenues for understanding the effects of therapies targeting fat and muscle composition.
| Key Findings | Details |
|——————|————-|
| Risk Factor | Intermuscular fat increases heart disease risk |
| Measurement | Fatty muscle fraction (ratio of intermuscular fat to total muscle and fat) |
| Impact | 1% increase in fatty muscle fraction = 2% higher CMD risk, 7% higher heart disease risk |
| Population | 669 patients, 70% female, 46% non-white |
| Follow-Up | Six years |
This study not only sheds light on the hidden dangers of intermuscular fat but also emphasizes the importance of personalized approaches to cardiovascular health. For more insights into how inflammation affects the body, visit this resource.The relationship between obesity, muscle fat, and cardiovascular health is under the microscope as researchers explore how treatments like weight-loss drugs and exercise impact metabolic heart disease. Professor Viviany Taqueti, Director of the Cardiac Stress Laboratory at Brigham and Women’s Hospital and Faculty at Harvard Medical School, is leading the charge. Her team is evaluating strategies such as exercise, nutrition, and weight-loss therapies to understand their effects on body composition and heart health.
“What we don’t know yet is how we can lower the risk for people with fatty muscles,” says Professor Taqueti.”Such as, we don’t know how treatments such as new weight-loss therapies affect fat in the muscles relative to fat elsewhere in the body, lean tissue, and ultimately the heart.”
Recent research published in the Journal of the european Society of Cardiology (ESC) highlights the complex interplay between obesity, muscle fat, and cardiovascular risk. Souza and colleagues found that increasing levels of intermuscular adipose tissue (IMAT) were associated with a higher occurrence of coronary microvascular dysfunction (CMD). Notably, the presence of both elevated IMAT and CMD was linked to the highest rate of future adverse cardiovascular events, self-reliant of body mass index (BMI).
Dr. Ranil de Silva from Imperial College London,UK,and colleagues emphasized in an accompanying editorial,”Obesity is a public health priority. Epidemiologic studies clearly show that obesity is associated with increased cardiovascular risk, though this relationship is complex.”
The study’s findings are intriguing but come with limitations. As a retrospective observational study, it did not directly evaluate potential mechanisms such as insulin resistance, endothelial function, or skeletal muscle physiology. “The data presented by Souza et al. are hypothesis generating and should stimulate further examination into establishing the added value of markers of adiposity to conventional and emerging cardiac risk stratification,” the editorial noted.
Key Findings at a Glance
Table of Contents
| Factor | Impact on Cardiovascular Health |
|———————————|—————————————————————————————————–|
| Intermuscular Adipose Tissue (IMAT) | higher levels associated with increased coronary microvascular dysfunction (CMD) |
| elevated IMAT + CMD | Highest rate of future adverse cardiovascular events, independent of BMI |
| Obesity | Complex relationship with cardiovascular risk, independent of muscle fat |
the study underscores the need for targeted cardiometabolic interventions in patients with CMD and elevated IMAT. As researchers continue to explore the role of treatments like glucagon-like peptide-1 receptor agonists and weight-loss therapies, the focus remains on understanding how these interventions affect fat distribution and heart health.
For more insights into the latest cardiovascular research, visit the European Society of Cardiology (ESC).
A groundbreaking study published in the European Heart Journal reveals that hidden pockets of fat within muscles, known as intermuscular fat, substantially increase the risk of heart attack, heart failure, and death. This discovery challenges the adequacy of conventional measures like body mass index (BMI) and waist circumference in assessing cardiovascular risk. To delve deeper into these findings, we sat down with Dr. Elena Martinez, a leading cardiologist and researcher specializing in metabolic health and cardiovascular disease.
Understanding Intermuscular Fat and Its Risks
Senior Editor (SE): Dr. Martinez, thank you for joining us. This study highlights intermuscular fat as a notable risk factor for heart disease. Can you explain what intermuscular fat is and why it’s so problematic?
Dr. martinez: Absolutely. Intermuscular fat, or intramuscular adipose tissue (IMAT), is fat that accumulates within skeletal muscles, rather than under the skin like subcutaneous fat. What makes it particularly concerning is its metabolic activity. This fat secretes inflammatory molecules and disrupts glucose metabolism, leading to insulin resistance and inflammation. Over time, these effects can impair blood vessel function and contribute to coronary microvascular dysfunction (CMD), which is a precursor to more severe heart conditions.
SE: So, it’s not just about how much fat someone has, but where it’s located?
Dr. Martinez: exactly. This study emphasizes that fat distribution matters more than total body fat or BMI in predicting cardiovascular risk. Someone with a normal BMI but high levels of intermuscular fat coudl be at greater risk than someone with a higher BMI but less of this hidden fat.
The Study’s Findings and Implications
SE: The study found that a 1% increase in fatty muscle fraction raised the risk of CMD by 2% and heart disease by 7%. What does this mean for clinical practice?
Dr. Martinez: These findings are a wake-up call for clinicians to look beyond traditional metrics like BMI. We need to develop better tools to assess fat distribution, especially in patients with symptoms like chest pain or shortness of breath but no signs of obstructive coronary artery disease. Imaging techniques like PET/CT scans, as used in this study, could play a crucial role in identifying high-risk individuals.
SE: The study also noted that subcutaneous fat didn’t considerably impact heart disease risk. Why is that?
Dr. Martinez: Subcutaneous fat is generally less metabolically active than intermuscular fat. While excess subcutaneous fat can still contribute to obesity-related health issues, it doesn’t have the same direct inflammatory and metabolic effects on the heart and blood vessels. that’s why intermuscular fat is such a critical focus.
The Role of Weight-Loss Therapies and Interventions
SE: With treatments like GLP-1 receptor agonists and weight-loss therapies gaining popularity, how do you see these findings influencing their use?
Dr. Martinez: This study raises significant questions about how these treatments affect fat distribution. Such as, do they reduce intermuscular fat, or do they primarily target subcutaneous fat? Understanding this could help us optimize these therapies for cardiovascular risk reduction. Additionally, combining pharmacological treatments with lifestyle interventions like resistance training to build lean muscle mass could be particularly beneficial.
SE: What about exercise? does it help reduce intermuscular fat?
Dr. Martinez: absolutely. Regular physical activity, especially resistance and strength training, can help reduce intermuscular fat while increasing lean muscle mass. This not only improves metabolic health but also directly benefits the heart.
Moving Forward: A Call for Personalized Care
SE: What’s the key takeaway for patients and healthcare providers?
Dr. Martinez: The takeaway is that cardiovascular health is highly individualized. We need to move away from a one-size-fits-all approach and focus on personalized strategies that address fat distribution, metabolic health, and inflammation. Patients should also be encouraged to engage in regular physical activity and maintain a balanced diet to reduce their risk.
SE: Thank you, Dr. Martinez,for sharing these valuable insights. This is clearly a pivotal moment in our understanding of cardiovascular risk and the importance of addressing hidden fat in muscles.
Dr. Martinez: My pleasure. It’s an exciting time in cardiology, and I’m hopeful that these findings will lead to better outcomes for patients.
For more insights into the latest cardiovascular research,visit the European Society of Cardiology (ESC).
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This interview provides a comprehensive look at the study’s findings and their implications for both patients and healthcare providers, underscoring the importance of addressing intermuscular fat in the fight against heart disease.
