The Cost of Extra Weight on Heart Failure Risk

Obesity is a growing problem around the world. While society often dismisses obesity as a lack of willpower or a personal failing, it is recognized as a disease by agencies as diverse as the US Food and Drug Administration (FDA), the World Health Organization (WHO), and the American Heart Association (AMA).^[1] Eating disorders and weight gain have a heritable component, and certain genes can predispose people to obesity.^[1] Hormonal imbalances can make diet and exercise more difficult, adding to weight gain.^[1] On top of this are social determinants of health: cheap, highly processed foods are high in fats, sugars, and preservatives, while healthier food remains prohibitively expensive for many. 

Unfortunately, obesity is associated with more than just social stigma. Obesity affects nearly every organ system, and symptoms present in different ways. We call this phenomenon the protean manifestations of obesity. The term “protean” comes from Proteus, a Greek sea god who could change his shape at will, and is used to emphasize the diverse ways in which obesity can impact health. It significantly increases the risks of developing serious health conditions such as type 2 diabetes, high blood pressure, and various heart problems, including heart failure.^[2]

When heart failure develops, it can lead to a range of serious symptoms. People with heart failure may have swelling in the legs, feel short of breath, get tired easily, and sense that their heart is racing. This occurs as the heart tries and fails to adequately deliver oxygen-rich blood throughout the body. Chronic heart failure is a serious condition with high mortality rates.^[3] 

Researchers estimate that 5-6 million Americans suffer from heart failure, although up to 50% of cases may go undiagnosed.^[2,3] The risk of developing heart failure is higher in older adults, especially those who smoke or have underlying conditions such as coronary artery disease, high blood pressure, diabetes, or obesity.^[2] As rates of these conditions - especially obesity - rise, the incidence of heart failure also rises.^[2]

Obesity is a major risk factor for developing heart failure.^[3] Large-scale studies show that each additional point of body mass index (BMI) can increase heart failure risk by 5-7%!^[3,4] Overweight people are more likely to develop heart disease, and obese people have a nearly 2-3 times higher risk.^[4,5] Obese women tend to be at the highest risk.^[4,5] But how does excess weight damage the heart?

Obesity is both a risk factor and a direct cause of heart failure because it changes how the body and heart function.^[3,6] Obesity is associated with changes in blood flow, elevated blood pressure, obstructive sleep apnea, diabetes, and kidney diseases.^[6] Excess body fat can alter our metabolism, leading to insulin resistance and promoting inflammation.^[6] These conditions alone may lead to heart failure, but the heart itself is also directly affected by obesity.^[3,6] The weight of the heart increases along with the weight of the body.^[3,6] As the heart tries to pump blood to the excess body mass, the heart pumps harder, increasing the thickness of the walls of the heart chamber.^[3,6] As the heart walls thicken, the volume inside the chamber decreases, and the heart cannot relax properly between beats. This reduces its ability to fill with blood and pump effectively. Over time, these changes can lead to heart failure.^[3,6]

One of the worst parts of obesity-related heart failure is that its symptoms - such as tiredness, inability to exercise, and poor sleep - can all contribute to obesity. This can lead to a feedback loop that needs to be broken. Weight loss is a clear candidate for increasing quality of life and decreasing mortality rates for obese people with heart failure.^[3] Weight loss can improve heart function, restore the heart’s structure, and lower the heart’s weight.^[7,8,3] A healthy diet and exercise are critical to improving weight and heart failure outcomes, but this clearly isn’t working for everyone. Many people may benefit from medications that help increase the feeling of fullness and modify how the body digests food. Clinical trials are currently looking to break the cycle of obesity and heart failure through weight loss medications.

Creative Director Benton Lowey-Ball, BS, BFA
 

References:

[1] Upadhyay, J., Farr, O., Perakakis, N., Ghaly, W., & Mantzoros, C. (2018). Obesity as a disease. Medical Clinics, 102(1), 13-33. https://www.medical.theclinics.com/article/S0025-7125(17)30128-1/abstract

[2] Groenewegen, A., Rutten, F. H., Mosterd, A., & Hoes, A. W. (2020). Epidemiology of heart failure. European journal of heart failure, 22(8), 1342-1356. https://onlinelibrary.wiley.com/doi/10.1002/ejhf.1858

[3] Alpert, M. A., Lavie, C. J., Agrawal, H., Aggarwal, K. B., & Kumar, S. A. (2014). Obesity and heart failure: epidemiology, pathophysiology, clinical manifestations, and management. Translational Research, 164(4), 345-356. https://www.sciencedirect.com/science/article/abs/pii/S1931524414001340

[4] Kenchaiah, S., Evans, J. C., Levy, D., Wilson, P. W., Benjamin, E. J., Larson, M. G., ... & Vasan, R. S. (2002). Obesity and the risk of heart failure. New England Journal of Medicine, 347(5), 305-313. https://www.nejm.org/doi/full/10.1056/NEJMoa020245

[5] Horwich, T. B., Fonarow, G. C., & Clark, A. L. (2018). Obesity and the obesity paradox in heart failure. Progress in cardiovascular diseases, 61(2), 151-156. https://www.sciencedirect.com/science/article/pii/S0033062018300951?via=ihub

[6] Ebong, I. A., Goff Jr, D. C., Rodriguez, C. J., Chen, H., & Bertoni, A. G. (2014). Mechanisms of heart failure in obesity. Obesity research & clinical practice, 8(6), e540-e548. https://www.sciencedirect.com/science/article/pii/S1871403X1300224X

[7] Oreopoulos, A., Padwal, R., Kalantar-Zadeh, K., Fonarow, G. C., Norris, C. M., & McAlister, F. A. (2008). Body mass index and mortality in heart failure: a meta-analysis. American heart journal, 156(1), 13-22. https://www.sciencedirect.com/science/article/pii/S0002870308001543