Obesity is increasingly recognized not just as a risk factor for cardiovascular disease, but as a direct driver of heart problems, independent of conditions like high blood pressure, diabetes, and high cholesterol. Recent research is revealing how excess weight alters heart muscle function and disrupts cholesterol processing, even in the absence of these traditionally recognized cardiovascular risk factors.
A Standalone Risk Factor
For years, the medical community understood obesity to increase cardiovascular risk indirectly, primarily by contributing to the development of hypertension, type 2 diabetes, and elevated cholesterol levels. However, emerging evidence suggests that the weight itself can directly impact the heart.
“Obesity seems to act on the heart independently, regardless of the presence of other factors like hypertension, high cholesterol, or diabetes,” explains Dr. Chiadi Ndumele, a cardiologist at Johns Hopkins, as reported in recent studies. “Over the long term, this can lead to heart failure.”
Dr. Ndumele’s team published a study in Journal of the American College of Cardiology: Heart Failure, following over 9,500 adults aged 53 to 73 who had no previously diagnosed heart disease. Researchers measured participants’ body mass index (BMI) and levels of troponin T, an enzyme released by heart cells when damaged. The results showed a clear correlation: higher BMI was associated with increased troponin T levels.
Over a 12-year monitoring period, individuals with severe obesity (BMI of 35 or higher) were most likely to develop heart failure. Those with both severe obesity and elevated troponin levels had a nine-fold increased risk of heart failure compared to participants with a normal weight and undetectable troponin.
The study also demonstrated that each five-point increase in BMI was associated with a 32% increase in the risk of heart failure.
How Obesity Alters Cholesterol Metabolism
Researchers at Boston University Chobanian & Avedisian School of Medicine have identified a biochemical mechanism explaining how obesity impacts the cardiovascular system. They discovered that in individuals with excess weight, low-density lipoprotein (LDL) particles – responsible for transporting cholesterol through the bloodstream – function differently.
“Our results show that in obesity, the quantity of LDL isn’t the main problem, but rather how it’s altered,” says Dr. Shobini Jayaraman, the study’s lead researcher. “The ‘bad’ cholesterol becomes even more aggressive against the backdrop of inflammation associated with obesity. Cholesterol transport shifts from a normal process to an altered one, and more cholesterol remains trapped in the artery walls, where it can form plaques that block circulation.”
The research, published in the Journal of Lipid Research, compared blood samples from patients with severe obesity before and 6 and 12 months after bariatric surgery to those of a control group with a normal weight. In obese patients, LDL particles were less efficient at transporting cholesterol to normal receptors and tended to deposit it in artery walls, a process underlying atherosclerosis. Following weight loss, the quality of LDL cholesterol gradually improved.
“Our study shows that as a patient’s weight normalizes, the quality of LDL continues to improve, indicating that the risk of cardiovascular disease continues to decrease,” explains Dr. Olga Gursky, a professor of pharmacology, physiology, and biophysics at Boston University. “This represents promising not only for patients who have undergone bariatric surgery but also for many others who are overweight or obese and are using various approaches to lose weight.”
Visceral Fat and Associated Risks
Subcutaneous fat, located directly under the skin, is generally less associated with medical problems. In contrast, visceral fat, stored around internal organs like the heart, liver, and intestines, has a clearer link to metabolic and cardiovascular diseases.
While a moderate amount of visceral fat is normal, its excess accumulation can lead to increased blood cholesterol, elevated blood pressure, and an increased risk of type 2 diabetes. The British Heart Foundation notes that these changes are part of the mechanism through which cardiovascular diseases develop.
Narrowing of the coronary arteries due to plaque buildup increases the risk of heart attack. Similar processes in the cerebral arteries can lead to stroke or vascular dementia.
Assessing Personal Risk
The World Health Organization (WHO) classifies obesity as a chronic, relapsing disease resulting from complex interactions between genetic, neurobiological, behavioral, and environmental factors. Increased access to inexpensive, calorie-rich processed foods, combined with increasingly sedentary lifestyles, has created what experts call obesogenic environments.
Two simple measurements can indicate whether excess weight is affecting health: body mass index (BMI) and waist-to-height ratio.
BMI is calculated by dividing weight (in kilograms) by the square of height (in meters). According to WHO classifications, for adults, values are interpreted as follows: 18.5-24.9 indicates a normal weight, 25-29.9 indicates overweight, and 30 or higher is considered obesity. Obesity is divided into three classes: class 1 (BMI 30-34.9), class 2 (BMI 35-39.9), and class 3 or severe obesity (BMI of 40 or higher). For example, for a person 1.75 m tall, severe obesity would mean approximately 123 kilograms or more.
BMI has limitations, as it doesn’t differentiate between fat and muscle mass and doesn’t account for age, sex, or body type. The British Heart Foundation recommends measuring the waist-to-height ratio, especially for individuals with a BMI under 35.
To calculate this ratio, measure waist circumference at the midpoint between the lower edge of the ribs and the upper edge of the hips, just above the belly button. Then, divide this value by height (both expressed in the same unit). A result between 0.4 and 0.49 indicates low risk, between 0.5 and 0.59 indicates increased risk, and 0.6 or higher indicates very high risk. In short, the waist should not be larger than half the height.
Warning Signs of Heart Failure
Individuals with obesity should be attentive to symptoms of heart failure:
- Persistent fatigue,
- Difficulty breathing,
- Irregular heartbeats.
“Obesity itself can cause silent damage to the heart muscle,” emphasizes Dr. Ndumele.
Doctors recommend regular monitoring of cardiovascular health indicators, such as BMI, blood pressure, blood sugar, and cholesterol. Regular evaluations and open discussions with a family doctor or specialist can help identify problems early.
Researchers at Johns Hopkins estimate that by 2030, one in five adults could have heart failure, and the increasing prevalence of obesity is likely contributing to this trend.
What Can Be Done for Weight Loss and Long-Term Maintenance
Dr. Chiadi Ndumele cautions that both patients and doctors may sometimes believe there is no cause for concern when blood pressure and blood sugar are within normal limits. “There may still be a form of cardiac damage that shows no obvious signs,” the American cardiologist says.
For weight loss, specialists propose a realistic target. A 5-10% reduction in body weight over approximately six months can bring about clear improvements in cardiovascular health.
“Excess weight is caused by many factors, such as genetics, biology, lifestyle, environment, and even events in your life. Eating less and moving more is not always the solution to losing weight and maintaining that weight loss,” explains www.adevaruldespregreutateata.ro.
In December 2025, the World Health Organization published its first global guidelines on the use of GLP-1 receptor agonist-based therapies in the treatment of obesity in adults. These medications, administered by injection, help control appetite and maintain weight loss in the long term. The guidelines emphasize that medication should be part of a comprehensive care program and is not a standalone solution.
Dr. Tedros Adhanom Ghebreyesus, WHO Director-General, stated: “Obesity is a treatable chronic disease through comprehensive and long-term care.”
For more information on weight management, visit www.adevaruldespregreutateata.ro
Article supported by Novo Nordisk Romania
