A new large study by U.S. researchers, published in the journal Circulation, found that even a few extra pounds and a little inactivity increased the risk of heart failure.
“The study findings suggest that overweight men who are not obese still have an increased risk of heart failure,” said Dr. Satish Kenchaiah, who conducted the research as an epidemiologist at Brigham and Women's Hospital in Boston and is now at the U.S. National Heart, Lung, and Blood Institute (NHLBI).
When it comes to exercise, “even small amounts of physical activity appear to decrease heart failure risk,” said Kenchaiah.
The “Physicians' Health Study” followed 21,000 male doctors over a period of two decades, measuring among other factors the influence of overweight and physical activity on the development of heart failure, also known as congestive heart failure.
The heart of a person who has been diagnosed with heart failure simply cannot pump blood in sufficient volume to satisfy the body's oxygen requirements. As the name suggests, the underlying condition (infection of the heart, coronary artery disease, diabetes, heart valve defect, high blood pressure, emphysema and others) weakens the heart muscle causing it to slowly deteriorate until it is unable to meet the body's requirements.
Obesity, defined as having a body-mass index, or BMI, of 30 or more, has long been known as a risk factor for heart failure. The study focused on men who were borderline obese with a BMI of 25 to 29.9.
About 5 percent of the doctors were considered obese and 40 percent overweight, at the start of the study. Adjusting for other risk factors including high cholesterol and high blood pressure, researchers found a 49 percent increased incident of heart failure in overweight men compared to those with a BMI under 25 or less. Heart failure incidence was 180 percent for obese men compared to the leaner ones.
When it came to physical activity there was a similar finding. “Men who engaged in physical activity from one to three times per month had an 18 percent reduction in heart failure risk,” Kenchaiah said. “For those who were active five to seven times per week, the reduction was 36 percent. The more you exercise the greater reduction you achieve.”
The association of even minimal activity with reduced risk could be explained as an indicator of good habits in general, he said. “It is possible that they have an overall healthier lifestyle.”
Researchers found that the doctors who rarely or never participated in physical activity were older, smoke cigarettes more often, and were more likely to have diabetes or high blood pressure.
“The new findings reinforce what we’ve said in the past,” said Dr. Gerald Fletcher, a preventive cardiologist at the Mayo Clinic in Jacksonville, Fla. “Overweight, not necessarily obese, is definitely a risk factor for heart failure.”
According to Dr. Kenchaiah, two-thirds of Americans have excess body weight and only 30 percent exercise regularly. More than five million Americans are living with heart failure and more than 500,000 cases are diagnosed each year. Most will die within eight years.
During the last nearly three decades, the number of people over the age of 65 who are hospitalized with heart failure more than doubled, representing a mounting burden on the health care system. #