The relationship between obesity and cardiovascular disease

Overweight and obesity increase the risk of cardiovascular diseases and mortality. Effective weight management and treatment not only reduce co-morbidities but also prevent cardiovascular diseases.

Reduce the risk of heart failure in obese individuals by 50% through weight loss

At the scientific seminar on “Multimodal treatment of obesity” held at the Tam Anh Research Institute (TAMRI) on the afternoon of April 1, doctors from Tam Anh General Hospital in Ho Chi Minh City discussed the current status of obesity and its relationship with cardiovascular diseases.

Master, Specialist Level 2 Doctor Huynh Thanh Kieu, Head of Cardiology Department 1 and Head of Heart Failure Unit at the Cardiovascular Center, shared that obesity is becoming a global epidemic. According to the 2015 Global Burden of Disease (GBD) Study, there are over 600 million obese adults worldwide, accounting for 39-49% of the population. Among the 4 million deaths associated with high BMI, two-thirds are attributed to cardiovascular diseases. Statistics from the U.S. in 2016 also show that the incidence of cardiovascular diseases in obese individuals ranges from 30-50%, three times higher than in people with normal weight.

The pathophysiological mechanism of obesity begins with overeating and consuming inflammatory substances like excess sugar and saturated fats, leading to adipocyte hypertrophy, fat accumulation in the abdomen and heart, secretion of inflammatory substances, disruption of the body’s metabolic regulation, increased fat toxicity, and insulin resistance, among other metabolic disorders.

Obesity is a risk factor for cardiovascular diseases through the promotion of hypertension, dyslipidemia, diabetes, and sleep apnea. Additionally, obesity accelerates atherosclerosis, contributing to coronary artery disease, peripheral artery disease, and ultimately heart failure. Obese individuals also have an increased risk of arrhythmias, especially atrial fibrillation, and sudden death. Furthermore, obesity leads to hypercoagulability, raising the risk of thrombosis and pulmonary hypertension, and heart valve disease due to metabolic disturbances, which can lead to aortic valve stenosis.

Master of Science, Specialist Level 2 Doctor Huynh Thanh Kieu analyzes cardiovascular-related obesity. Photo: Tam Anh Research Institute

Obesity leads to excessive fat accumulation, resulting in fundamental metabolic disruptions such as insulin resistance, chronic inflammation, dyslipidemia, endothelial dysfunction, hypercoagulability, and atherosclerosis. This contributes to inflammation and fat buildup in the epicardial layer of the heart, adjacent to the coronary vessels and cardiomyocytes, leading to coronary atherosclerosis, atrial conduction disturbances, atrial arrhythmias, and increased cardiac workload, ultimately resulting in heart failure.

“Individuals with high visceral fat have the highest risk of cardiovascular diseases, regardless of their BMI,” Dr. Kieu said.

Overweight and obesity are also closely linked to conditions such as diabetes, hypertension, and sleep apnea syndrome, which lead to heart failure and atrial fibrillation. Obesity exacerbates atherosclerosis and coronary circulation abnormalities, worsening myocardial ischemia and increasing cardiovascular risks.

Dr. Kieu explained that, in the Birmingham study, each additional unit of BMI increased the risk of heart failure by 5-7%. Visceral obesity directly affects the heart muscle, causing cardiomyocyte hypertrophy, myocardial fibrosis, inflammation, increased circulatory volume, and increased myocardial load. Weight reduction can lower the risk of heart failure in obese individuals by up to 50%.

Master of Science Level 2 Huynh Thanh Kieu, Associate Professor, Doctor of Medicine Pham Nguyen Vinh, Associate Professor Pham Thi Thu Ha (from left to right) participated in the seminar. Photo: Tam Anh Research Institute

Furthermore, each 5-unit increase in BMI raises the risk of sudden death by 16% because obese individuals are more prone to ventricular arrhythmias. The study revealed that 20% of atrial fibrillation cases are seen in obese patients, and each 5-unit increase in BMI raises the risk of new atrial fibrillation by 29%. Cardiac MRI performed in regions of the myocardium with extensive epicardial fat reveals conduction disturbances in the atria, increasing the risk of atrial arrhythmias. “Reducing 10% of body weight reduces the risk of atrial fibrillation recurrence by six times,” Dr. Kieu said.

Moreover, obese individuals face significant limitations in diagnostic tests such as electrocardiograms, ultrasounds, and stress tests, reducing the effectiveness of resuscitation efforts. Some individuals exceed the weight limits of imaging diagnostic machines such as CT and MRI.

Therefore, weight control and management of co-morbidities are key strategies in reducing cardiovascular risks in obese individuals.

The role of GLP-1 in cardiovascular safety

Dr. Pham Thi Thu Ha, from the Tam Anh General Hospital Weight Loss Center, explained at the seminar that GLP-1 is a hormone essential in metabolism and blood sugar regulation, affecting various organs such as the pancreas, liver, brain, heart, stomach, and lungs.

Specialist Level 1 Doctor Pham Thi Thu Ha presented the role of GLP-1 in weight loss and cardiovascular safety. Photo: Tam Anh Research Institute

GLP-1 helps regulate blood sugar by acting on the pancreas and liver, delays gastric emptying in the stomach, stimulates the brain to reduce appetite, and reduces food and calorie intake, facilitating weight loss in obesity treatment.

In terms of cardiovascular health, GLP-1 offers protective effects on the heart by reducing inflammatory factors, protecting nerves, and influencing lipid metabolism. This hormone has a broad effect, helping to regulate blood sugar, promote weight loss, and protect cardiovascular health.

Dr. Ha mentioned that patients with type 2 diabetes often experience elevated cardiovascular risks. Studies on GLP-1 receptor agonists for cardiovascular health are ongoing, with results showing that GLP-1 reduces cardiovascular events and cardiovascular mortality.

Certain GLP-1 drugs have proven to have a dual effect, controlling both blood sugar and cardiovascular diseases.

Dr. Lam Van Hoang, Director of the Tam Anh General Hospital Weight Loss Center, shared information about weight loss treatment at the seminar. Photo: Tam Anh Research Institute

At the seminar, Dr. Lâm Văn Hoàng emphasized that obesity has various causes, and treatment must be tailored to each patient based on clinical testing. The use of GLP-1 receptor agonists in weight loss treatment is well-established and effective in reducing cardiovascular risks.

Associate Professor Dr. Pham Nguyen Vinh, Director of the Cardiovascular Center, affirmed that obesity is linked to several diseases, such as diabetes and hypertension, which impact cardiovascular health. By managing weight and treating obesity effectively, individuals can prevent cardiovascular diseases.