Nearly 78 million American adults are obese. Obesity is a major public health problem, ranking fifth on the World Health Organization’s list of leading risk factors for mortality. Not too surprisingly, this worldwide epidemic is also closely linked to the rise in the incidence of cardiovascular disorders, particularly heart failure.
A 2010 review in the Journal of the American College of Cardiology cited obesity as an increasingly important risk factor for heart failure, noting the metabolic abnormalities associated with obesity appear to stress the circulatory system and set the stage for heart failure.
Weight control affects cardiac function, says Thomas H. Marwick, Ph.D., professor of medicine at the University of Queensland at Princess Alexandra Hospital in Brisbane,
Australia. A study compared the left ventricles of normal-weight people, with the left ventricles of severely obese people, and found that in the obese participants, there was a very weakened ability of cardiac muscle to contract and a diminished ability of cardiac muscle to fully relax.
The full-relax is important for enabling the ventricle to be refilled with blood during rest periods between the heartbeats. The study showed impairments of left ventricular function in mildly obese, as well as overweight, subjects. “The study showed a direct relationship between the level of obesity and the degree of myocardial dysfunction,” remarks Marwick. And this finding was independent of other risk factors. “We think this indicates a direct metabolic effect of obesity on the heart muscle.”
Every 1-point rise in a person’s body mass index increases the risk for heart failure by 5 to 7 percent, according to a study published in 2002 in the New England Journal of Medicine. Obese people — those with a BMI above 30 – were found to be twice as likely to develop heart failure as normal-weight subjects. The statistical relationship between heart failure and obesity remained strong even when other obesity-related risk factors for heart failure, such as high blood pressure and diabetes, were accounted for.
“Obesity is at least as great a risk factor for heart failure as it is for heart attack or stroke,” stated John McMurray, professor of cardiology at the Western Infirmary, Glasgow, in a presentation at the Heart Failure Congress in 2009 in his discussion of the findings from Euroaspire, Europe’s largest survey of cardiovascular risk factors in coronary patients, which found increased from 25 percent in 1997 to 38 percent in just ten years – and this in people who had already had at least one heart attack.
As America’s waistline increases, so too does the cost to the healthcare system. Reuters reports that the price tag for obesity in the U.S. is close to $200 billion a year, exceeding smoking as public health enemy number one when it comes to cost. A 2012 study in the American Journal of Preventive Medicine estimated that by 2030 obesity will rise from 34.5% of the adult population to 42%, with related health care spending forecast to rise to an astounding $550 billion. Making the cost impact all the more troubling is the fact that, unlike smokers, obese people tend to live almost as long as those who keep their weight under control. “Smokers die early enough that they save Social Security, private pensions, and Medicare trillions of dollars,“ notes Eric Finkelstein of Duke University, paradoxically.
There is hope, though. If adults across America could reduce their body mass index by just 5 percent, savings in health care costs could be as much as 7.9 percent – and millions could avoid a stroke or cardiovascular disease — notes a Robert Wood Johnson Foundation Health Group study. Fat chance of that happening, say most of the critics.
SOURCE: HEART FAILURE TODAY