Obesity may not be bad for heart failure patients
By Merritt McKinney
NEW YORK, Aug 31 (Reuters Health) - The link between obesity and an increased risk of heart failure and other cardiovascular illnesses is well known. But for people who already have heart failure, being obese or overweight may not be a disadvantage, researchers in California report.
In a study of about 1,200 people with advanced heart failure, survival rates were similar regardless of body mass index (BMI), a measure of obesity that takes into account weight and height.
In fact, one and two years after the start of the study, obese individuals were more likely to be alive than thinner patients, researchers report in the September issue of the Journal of the American College of Cardiology. By the fifth year of the study, this advantage had disappeared, however, and survival rates were similar across the BMI spectrum.
"The finding in this study that being overweight or obese did not increase heart failure mortality and was, in fact, associated with better 1- and 2-year survival was quite unexpected," one of the study's authors, Dr. Gregg C. Fonarow of the University of California, Los Angeles, told Reuters Health.
He noted that doctors often advise overweight and obese patients with heart failure to lose weight based on the idea that carrying around extra pounds reduces their survival odds. The appropriateness of these recommendations has been untested, however, since the link between obesity and poor heart-failure survival odds has not been proved, according to Fonarow.
"Understanding how and why obesity may be protective in patients with established heart failure may lead to new treatments for heart failure," he said. One possible explanation, according to the UCLA researcher, is that obese patients may have less activation of so-called neurohormones. He noted that overactivation of these hormones is known to increase the risk of death in patients with heart failure.
The results question the wisdom of advising heart failure patients to lose weight, Fonarow noted. "Clinical trials will need to be performed to see if weight loss for overweight and obese heart failure patients is beneficial or of little value," he said.
In particular, the use of weight-loss drugs, which carry certain risks, "should be weighed against the now uncertain benefits of weight loss," Fonarow added.
But the study finding does not mean that people without heart failure do not need to worry about keeping their weight under control, he told Reuters Health.
"Obesity has been well established to be associated with adverse health consequences such as an increased risk of diabetes and heart attacks," Fonarow said.
"For individuals without heart failure, the finding that obesity did not increase heart failure mortality should not in any way be viewed as support for allowing oneself to become overweight or obese," he stated.
And Fonarow added that regardless of weight status, all patients with heart failure have a considerable risk of dying from the disease. This means that all patients should be treated with appropriate medications, which include ACE inhibitors, beta-blockers and other drugs.
"Whether weight loss will help lower risk in patients with established heart failure is now, however, very much in question," he said.
Heart failure is a condition in which the heart becomes enlarged and can no longer pump blood efficiently. Symptoms include breathlessness, swelling of the feet due to fluid accumulation, and fatigue. Although treatment for the condition has improved, it remains a leading cause of hospitalization in the United States.
SOURCE: Journal of the American College of Cardiology 2001;38:789-795.
|