How Does Bariatric Surgery Affect Heart Disease?

How Does Bariatric Surgery Affect Heart Disease?

According to the World Health Organization (WHO), there are approximately 600 million obese adults across the world and 1.9 billion who are overweight.1 Obesity is a condition characterized by the accumulation of body fat more than what is required for the normal functioning of the various systems of the body. It is determined by body mass index (BMI), where a BMI of more than 25 is defined as being overweight and a BMI of more than 30 is considered obese. Apart from its aesthetic disapproval, obesity has long been associated with various heart diseases such as heart failure and coronary heart disease (CHD), which can all be fatal. The risk of CHD alone is 50 to 72% in obese or overweight individuals.2

Obesity affects the factors that can cause heart diseases:

  • Increases blood pressure and bad cholesterol (triglyceride and LDL)
  • Decreases good cholesterol (HDL)
  • Trigger diabetes (which can increase the risk of heart attack)

It also affects the normal functioning of the heart. With every point rise in BMI, scientists have found a 4% increased risk of abnormal heart function.3

  • The heart has to work harder to meet the high metabolic demand of an overweight body. It adapts by the enlargement of the left ventricle (heart chamber that pumps blood to the body). This raises the risk of heart failure, heart attacks and irregular heartbeats.
  • Increased cholesterol accumulates and blocks blood vessels, compromising the supply of oxygen to the heart and the rest of the body.
  • The hormone leptin released from the fat tissue can cause insulin resistance and damage healthy heart cells.

Luckily, obesity is a modifiable risk factor; which means that a drop on the scales can significantly improve the health of the heart. Bariatric surgery is an effective treatment for morbidly obese individuals, and the co-existence of other conditions such as heart diseases is a significant indication for surgery. Surgery is performed to either reduce the size of the stomach, restricting the amount of food intake, or to bypass a section of the intestine so less food is absorbed. Through bariatric surgery, an individual can achieve up to 40% weight loss.4 This in turn, lowers the risk factors of heart diseases by about 50% and risk of associated death by about 40%,5 by improving the heart’s structure and functioning. According to various studies:

  • The risk of circulatory and cardiovascular diseases was reduced by 72% in 5 years.4
  • In particular, the risk of death due to coronary artery disease was 59% lower.4
  • Total cholesterol and triglycerides reduced, HDL increased by 40% and LDL improved.6
  • The thickness of the left ventricle muscles declined significantly, decreasing blood volume and resting metabolic demand.4
  • High-sensitivity C-reaction protein, an inflammatory marker that rises the risk for heart attacks, fell by 80%.6
  • Many stopped taking medication for heart problems.6

With a healthy weight, the blood circulates freely without any blockages, the heart functions well and heart diseases are kept at bay. No other form of weight-loss regime has been found to achieve comparable results in a short span of time as bariatric surgery.


  1. Obesity and overweight. WHO website. Updated January 2015. Accessed January 22, 2016.
  2. Eckel RH. Obesity and Heart Disease: A Statement for Healthcare Professionals From the Nutrition Committee, American Heart Association. Circulation. 1997;96:3248-3250.
  3. The Effect of Obesity on Heart Function. American College of Cardiology Foundation website. March 15, 2011. Accessed January 22, 2016.
  4. Ashrafian H, Roux CW, Darzi A, Athanasiou T. Effects of Bariatric Surgery on Cardiovascular Function. Circulation. 2008;118:2091-2102.
  5. Kwok CS, Pradhan A, Khan MA, et al. Bariatric surgery and its impact on cardiovascular disease and mortality: A systematic review and meta-analysis. Int J Cardiol. 2014 Apr 15;173(1):20-8.
  6. New Stanford University Study Shows Risk Factors for Heart Attack Remain Low Seven Years after Gastric Bypass [news release]. San Diego, CA: American Society for Metabolic & Bariatric Surgery; June 20, 2012. Accessed January 22, 2016.