Recent research led by UCL (University College London) has brought to light an important finding for people living with obesity: weight loss surgery, or bariatric surgery, may significantly reduce the risk of developing heart failure by improving blood flow through the heart muscle. This study, published in the journal JACC: Cardiovascular Imaging, reveals that the adverse cardiovascular effects associated with obesity could be, at least in part, reversible through this surgical intervention.
The Link Between Obesity and Heart Failure
Obesity is a growing global health concern, with numerous associated risks, including heart failure. Individuals living with obesity are at an increased risk of developing heart failure, a condition where the heart is unable to pump blood efficiently, leading to symptoms like shortness of breath, fatigue, and fluid retention. The link between obesity and heart failure is complex, but one contributing factor is thought to be reduced blood flow through the small vessels in the heart, known as microvascular dysfunction.
In people with obesity, the heart has to work harder to pump blood, leading to structural changes such as thickened heart walls. These changes are often accompanied by decreased blood flow through the heart muscle, contributing to the increased risk of heart failure. The study conducted by UCL and King’s College London researchers aimed to explore whether the harmful cardiovascular effects of obesity could be mitigated by significant weight loss achieved through bariatric surgery.
The Cardiovascular Benefits of Bariatric Surgery
The research team, led by Professor Charlotte Manisty of the UCL Institute of Cardiovascular Science, conducted a detailed study involving 27 patients who underwent bariatric surgery. The patients, all living with obesity, had a median body mass index (BMI) of 44 kg/m² before surgery, which is significantly higher than the average BMI of 25 kg/m² typically seen in healthy individuals of the same age and sex.
The study utilized a sophisticated imaging technique known as quantitative perfusion magnetic resonance imaging (MRI) to measure blood flow through the smallest vessels in the heart muscle, both before and six months after surgery. This technique allowed researchers to accurately assess the impact of weight loss on the heart’s microvascular function, offering new insights into the potential cardiovascular benefits of bariatric surgery.
Weight Loss Surgery May Improve Heart Function and Reduces Risk Factors
The results of the study were striking. Six months after bariatric surgery, patients had lost an average of 29 kg (approximately 64 pounds), a significant reduction in body weight. This weight loss was accompanied by several key improvements in cardiovascular health:
1.Increased Blood Flow Through the Heart Muscle
One of the most notable findings was the increase in blood flow through the heart’s small vessels. Before surgery, patients showed reduced blood flow compared to healthy volunteers. However, six months post-surgery, there was a marked improvement in blood flow, indicating that the microvascular dysfunction associated with obesity was at least partially reversible.
2. Reduction in Heart Wall Thickness
The study also observed a reduction in the thickness of the heart walls. Thicker heart walls are a sign that the heart is working harder to pump blood, a condition often seen in people with obesity. The reduction in wall thickness post-surgery suggests that the heart was under less strain after weight loss, improving its overall function.
3. Remission of Type 2 Diabetes
Type 2 diabetes, a common comorbidity in people with obesity, showed significant improvement following bariatric surgery. Thirteen out of the seventeen patients who had type 2 diabetes before surgery were in remission six months later. This remission is crucial, as diabetes is a major risk factor for cardiovascular disease and heart failure.
4. Improved Lipid Profile
The surgery also led to improvements in the patients’ lipid profiles. Levels of triglycerides, a type of fat in the blood, decreased, while levels of HDL (high-density lipoprotein), often referred to as “good” cholesterol, increased. A healthier lipid profile is associated with a lower risk of developing cardiovascular disease.
5. Reduction in Liver Fat and Lower Blood Pressure
Another significant finding was the reduction in fat around the liver, a marker of the amount of fat stored around the abdominal organs. Excessive fat in this area is associated with an increased risk of cardiovascular disease and other metabolic disorders. Additionally, patients experienced a reduction in blood pressure, further decreasing their risk of heart disease.
Weight Loss Surgery as a Cardiovascular Intervention
The study’s findings provide compelling evidence that weight loss surgery can offer significant cardiovascular benefits for people living with obesity. By improving blood flow through the heart’s small vessels, reducing heart wall thickness, and improving other risk factors such as diabetes, lipid levels, and blood pressure, bariatric surgery appears to reduce the risk of developing heart failure.
Professor Manisty emphasized the importance of these findings, stating, “Previous research has suggested that weight loss surgery can reduce the risk of developing or dying from cardiovascular disease in people living with obesity. Our work provides a new, additional explanation for the benefits of this intervention.”
These results suggest that the cardiovascular benefits of weight loss surgery extend beyond the well-known effects on body weight and diabetes. The improvements in microvascular function observed in this study highlight the potential for bariatric surgery to not only reduce the risk of heart failure but also to reverse some of the damaging effects that obesity has on the heart.
For individuals living with obesity, the study underscores the importance of addressing cardiovascular risk factors. Weight loss, whether achieved through surgery, diet, or other means, can have profound effects on heart health. As the prevalence of obesity continues to rise worldwide, interventions like bariatric surgery may play an increasingly important role in reducing the burden of heart disease and improving overall public health.
In conclusion, this study adds to the growing body of evidence supporting the cardiovascular benefits of weight loss surgery for people living with obesity. By improving blood flow through the heart muscle and addressing other key risk factors, bariatric surgery offers a promising approach to reducing the risk of heart failure and enhancing long-term heart health.
