High Levels Of Leisure-time Physical Activity Cut Stroke Risk

"People should increase their physical activity during leisure time orcommuting to lower the risk of stroke," said lead investigator Gang Hu,Ph.D., senior researcher in the Department of Epidemiology and HealthPromotion at the National Public Health Institute in Helsinki, Finland.

The study is the first to find an inverse association betweenleisure-time physical activity and the risk of any stroke -- ischemicstroke, subarachnoid hemorrhage (bleeding from a vessel on the surfaceof the brain into the space between the brain and the skull), orintracerebral hemorrhage (bleeding inside the brain).

Stroke is the third leading cause of death in the United States.

Researchers reviewed data on 47,721 Finns ages 25 to 64 years who didnot have a history of coronary heart disease, stroke or cancer. Theycompleted questionnaires on smoking habits, alcohol consumption,socioeconomic factors, medical history, and physical activities duringtheir leisure time, at work and while commuting. During an averagefollow up of 19 years, 2,863 strokes occurred.

Hu said that the strengths of the study were its large sample size andin recording the largest number of strokes during its follow up.Self-reported leisure-time physical activities were classified in threeways:

• Low: almost completely inactive activities such as reading, TV viewing or minor physical activity;
• Moderate: physical activity for more than four hours a week, such as walking, cycling, light gardening, but excluding travel to work; and
• High: vigorous physical activity for more than three hours a week, such as running, swimming or heavy gardening. Hazard ratios for stroke, which indicate risk, were estimated for the different levels of leisure-time physical activities as well as occupational and commuting physical activities. Researchers adjusted for such factors as age, gender, body mass index, blood pressure, cholesterol, education, smoking, alcohol consumption and diabetes. They found that participants who described their leisure-time physical activity as moderate had a 14 percent lower risk of suffering any type of stroke than those whose activity level was low. Similarly, participants who reported high leisure-time physical activity had a 26 percent lower risk of all stroke than those who had a low physical activity level. Compared to participants with low activity levels, the risk of ischemic stroke was:
• 13 percent lower for those who reported that they were moderately active during leisure times; and
• 20 percent lower among participants who said they were highly active. Subarachnoid stroke risk was:
• 13 percent lower among participants with moderate activity; and
• 54 percent lower among those with high activity levels. Intracerebral hemorrhage risk was:
• 23 percent lower for those with a moderate activity level; and
• 37 percent lower for those with a high activity level.

Lowerrisk also was associated with increased amounts of physical activitywhile commuting. Commuter activity ranged from no activity, to 1 to 29minutes of activity (moderate), to more than 30 minutes of physicalactivity (high).

"Daily walking or cycling to and from work also reduces ischemic strokerisk and, therefore, should be recommended to all people," Hu said.Compared to people registering no activity while commuting to or fromwork, the risk of total stroke was 8 percent lower for those who werephysically active for one to 29 minutes on their way to work each day.It was 11 percent lower for people who were active for more than 30minutes on their way to work.

The risk of ischemic stroke was 7 percent lower for moderate commuting activity and 14 percent lower for high commuter activity.There was no association between commuter physical activity and hemorrhagic strokes.

"Since the increase in computerization and mechanization has resultedin ever-increasing numbers of people being sedentary for most of theirworking time, adding short time exercise during working breaks oradding walking activity during work time is recommended. We believe itwould be cost efficient for employers," Hu said.

This study was supported in part by grants from the Finnish Academy,the Ministry of Education and the Finnish Foundation for CardiovascularResearch.

Co-authors are: Cinzia Sarti, Ph.D.; Pekka Jousilahti, Ph.D.; KarriSilventoinen, Ph.D.; No--l C. Barengo, M.D.; and Jaakko Tuomilehto,Ph.D.

Editor's note: For more information on stroke, visit the American Stroke Association Web site: strokeassociation.org.