All Kinds of Activity Cut Future Risk of HF

September 21, 2010

September 21, 2010 (Baton Rouge, Louisiana) — The first study to examine whether different types of exercise affect the subsequent development of heart failure has shown that moderate and high levels of occupational or leisure-time physical activity are associated with a reduced risk [1].

Although there is strong evidence that regular physical activity has a protective effect against coronary heart disease and stroke, studies related to regular physical activity and HF are sparse and the results inconsistent, Yujie Wang (Pennington Biomedical Research Center, Baton Rouge, LA) and colleagues explain in their paper in the September 28, 2010 issue of the Journal of the American College of Cardiology. In addition, physical activity has always been represented by leisure-time activity, whereas the relationship of HF with occupational or commuting activity remains unclear, they add.

Senior author of the study, Dr Gang Hu (Pennington Biomedical Research Center), told heartwire : "This is the first time it has been shown that moderate- to high-intensity exercise can reduce the risk of HF in both men and women and that it is not just leisure-time activity that is important. Occupational and commuting activity can also reduce the risk of developing HF."

Hu stressed that this study was not designed to look at the effects of exercise in patients with heart failure; rather it looked at future development of the condition, with a mean follow-up of 18 years.

Women Walked or Cycled to Work More Often Than Men

The researchers used Finnish data from seven independent population surveys carried out in six geographic regions of Finland during the 1970s, 1980s, and 1990s and including 28 334 men and 29 874 women aged 25 to 74 and free of HF at baseline.

Occupational, commuting, and leisure-time physical-activity levels were assessed using a self-administered questionnaire only at baseline, with subjects reporting their occupational physical activity according to the following three categories: low was defined as physically very easy, sitting office work; moderate was work that included standing and walking; and high included walking and lifting at work or heavy manual labor.

Daily commuting (to work and back home) was also divided into three categories: motorized transportation or no physical work (no walking or cycling); walking or bicycling one to 29 minutes per day; and walking or bicycling more than 30 minutes per day. Finally, self-reported leisure-time physical activity was classed as the following: low was almost completely inactive, such as reading, watching TV, or doing some minor physical activity; moderate was some physical activity for more than four hours per week, such as walking, cycling, or light gardening, excluding travel to work; and high was defined as performing vigorous physical activity more than three hours week, such as running, jogging, swimming, heavy gardening, or competitive sports several times a week.

During a mean follow-up of 18.4 years, HF developed in 1868 men and 1640 women. The multivariate adjusted hazard ratios (HRs) show that occupational and leisure-time activity was inversely related with HF risk in both sexes, while active commuting had an inverse association with HF risk in women, but not in men, before adjustment for occupational and leisure-time physical activity. An explanation for the latter finding could be that women tended to walk or cycle to work more frequently than men, Hu told heartwire .

Hazard Ratio of HF* Associated With Occupational Activity

Group Light occupational activity Moderate occupational activity High occupational activity p for trend
Men 1.00 0.90 0.83 0.005
Women 1.00 0.80 0.92 0.007

*Adjusted for age, smoking, education, alcohol consumption, body-mass index, systolic blood pressure, total cholesterol, history of MI, valvular heart disease, diabetes, lung disease, use of antihypertensive drugs, and other types of physical activity

Hazard Ratio of HF* Associated With Leisure-Time Activity

Group Low leisure-time physical activity Medium leisure-time physical activity High leisure-time physical activity p for trend
Men 1.00 0.83 0.65 <0.001
Women 1.00 0.84 0.75 <0.001

*Adjusted for age, smoking, education, alcohol consumption, body-mass index, systolic blood pressure, total cholesterol, history of MI, valvular heart disease, diabetes, lung disease, use of antihypertensive drugs, and other types of physical activity

Joint Effects of More Than One Type of Exercise Protective

Effects of occupational physical activity have largely been ignored in epidemiologic surveys, Wang et al say, but the finding of a protective effect of moderate or high occupational activity on the risk of developing HF "is highly relevant to the improvement of health and longevity among working-aged people, because the increase in computerization and mechanization during the last decades has resulted in ever-increasing numbers of people being sedentary for most of their working time."

And although they note that they were unable to demonstrate an inverse association between active commuting alone and the risk of HF in both men and women, they say that their results still show that an individual with moderate or high leisure-time or occupational physical activity experienced further reductions in risk of HF when he or she was also engaged in commuting physical activity.

"This is an important finding because daily active commuting is a major source of total physical activity in some populations, can be implemented virtually everywhere, and is inexpensive," they observe.

The protective effect of physical activity on development of HF may in part be mediated by its effects on other risk factors for HF, such as BP, lipid profile, insulin sensitivity, and body weight, Wang et al conclude.

The study was supported by grants from the Finnish Academy and special research funds of the Social Welfare and Health Board of the city of Oulu, Finland. The authors report that they have no relationships to disclose.