Middle-aged people who bump their weekly exercise up to recommended levels over as little as six years may significantly decrease their risk of heart failure, a study finds.
Conversely, as little as six years without physical activity in middle age is linked to an increased risk of the cardiac disorder, which affects an estimated 5 million to 6 million Americans.
Researchers analyzed self-reported physical activity levels over time in more than 11,000 American adults.
“Our findings suggest that consistently participating in the recommended 150 minutes of moderate to vigorous activity each week… in middle age may be enough to reduce your heart failure risk by 31 percent,” says Chiadi Ndumele, assistant professor of medicine at Johns Hopkins University School of Medicine and senior author of the study. “Going from no exercise to recommended activity levels over six years in middle age may reduce heart failure risk by 23 percent.”
Unlike heart attack, in which heart muscle dies, heart failure involves a long-term chronic inability of the heart to pump enough blood hard enough to bring needed oxygen around the body. The leading cause of hospitalization in those over 65, the disorder’s risk factors include high blood pressure, high cholesterol, diabetes, smoking, and a family history.
The study, which appears in the journal Circulation, doesn’t show a direct cause-and-effect link between exercise and heart failure. But the data suggest it may never be too late to reduce the risk of heart failure with exercise, the researchers say.
“The population of people with heart failure is growing, because people are living longer and surviving heart attacks and other forms of heart disease,” says Roberta Florido, cardiology fellow at Johns Hopkins. “We don’t have specifically effective drugs to prevent heart failure, so we need to identify and verify effective strategies for prevention and emphasize these to the public.”
There are drugs that treat heart failure, such as beta blockers and ACE inhibitors, but they are not preventive; they work instead to reduce the heart’s workload after dysfunction arises.
Several studies, Florido says, have suggested that in general people who are more physically active have lower risks of heart failure, but little has been known about the impact of changes in exercise levels over time on heart failure risk.
How much exercise do you get?
The researchers used data gathered from 11,351 participants in the federally funded long-term Atherosclerosis Risk in Communities study, recruited from 1987 to 1989 in Forsyth County, North Carolina; Jackson, Mississippi; greater Minneapolis; and Washington County, Maryland.
Researchers monitored participants annually for an average of 19 years for cardiovascular disease events such as heart attack, stroke, and heart failure. Researchers gathered data using telephone interviews, hospital records, and death certificates. Over the course of the study, there were 1,693 hospitalizations and 57 deaths due to heart failure.
At the first and third ARIC study visits (six years apart), each participant rated his or her physical activity as poor, intermediate, or “recommended,” in alignment with guidelines issued by the American Heart Association.
The “recommended” amount was at least 75 minutes per week of vigorous intensity or at least 150 minutes per week of moderate intensity exercise. One to 74 minutes of vigorous intensity or one to 149 minutes of moderate exercise per week counted as intermediate. No exercise at all qualified as “poor.”
After the third visit, 42 percent of participants said they performed recommended levels of exercise; 23 percent said they performed intermediate levels; and 35 percent said they had poor levels of activity. From the first to the third visit, 24 percent of participants increased their physical activity; 22 percent decreased it; and 54 percent stayed in the same category.
Those with recommended activity levels at both the first and third visits showed the most heart failure risk decrease, at 31 percent compared with those with consistently poor activity levels.
Heart failure risk decreased about 12 percent in the 2,702 participants who increased their physical activity from poor to intermediate or recommended, or from intermediate to recommended, compared with those with consistently poor or intermediate activity ratings.
Heart failure risk increased by 18 percent in the 2,530 participants who reported decreased physical activity from visit one to visit three, compared with those consistently at recommended or intermediate activity levels.
According to the American Heart Association, fewer than 50 percent of Americans get recommended activity levels.
Other authors of the study are from Johns Hopkins, Baylor College of Medicine, the Cleveland Clinic, Brigham and Women’s Hospital, and the University of Minnesota.
Funding came from Johns Hopkins, the Robert Wood Johnson Foundation, and the National Institutes of Health.
Source: Johns Hopkins University