April 7, 2009 -- Belly fat may make heart failure more likely, and exercise may help heart failure patients.
That's the bottom line from three new studies on heart failure. Heart failure does not mean that the heart has stopped working; it means the heart is unable to pump enough blood to meet the body's needs.
The belly fat study is based on data from Sweden, where researchers followed more than 80,000 men and women for up to seven years to see who developed heart failure.
Participants reported their height, weight, and waist circumference at the study's start.
People with extra weight, especially around the waist, were more likely to develop heart failure during the study.
Bigger waistlines were linked to greater risk of heart failure for women, regardless of whether their BMI (body mass index) was normal, overweight, or obese. BMI and waist circumference both predicted heart failure risk in men.
The belly fat findings appear in the advance online edition of Circulation: Heart Failure.
Meanwhile, other researchers report in the Journal of the American Medical Association that exercise can be safe and effective for heart failure patients.
Their evidence comes from the largest study to date of exercise for heart failure patients.
Exercise and Heart Failure Study
More than 2,300 heart failure patients in the U.S., Canada, and France took part. They were screened to make sure they were healthy enough to exercise, and said they were willing to work out.
The researchers divided the patients into two groups.
All of the patients got standard medical care for their heart failure. In addition, one group of patients was assigned to get regular aerobic exercise.
Their workouts involved walking or using a treadmill or stationary bike three times per week, starting with 15- 30 minutes per session and boosting their workouts' length and intensity as the months passed.
Their first 36 workouts were supervised. After that, they were supposed to exercise at home using the heart monitors and stationary bikes or treadmills that the researchers supplied.
For comparison, patients in the other group weren't assigned to exercise.
Those patients could work out if they wanted to, but they didn't get any exercise training as part of the study. Many of those patients -- 55% -- weren't thrilled to be in the no-exercise group, and 8% reported exercising regularly throughout the study.
Overall, exercise was "well-tolerated and safe," write the researchers, who included Christopher O'Connor, MD, of the Duke Clinical Research Institute in Durham, N.C.
Exercise also had a "modest" effect on lowering the likelihood of death or hospitalization.
After screening out certain high-risk patients, exercisers were 11% less likely to die of any cause or be hospitalized for any cause during the study and 13% less likely to die of cardiovascular causes or be hospitalized because of heart failure, heart transplantation, or needing a heart pump implanted.
Quality of life was higher and disability was lower for the exercisers, according to surveys they completed.