(RxWiki News) A stroke can be a scary, even deadly, medical emergency. But before this emergency strikes, there are several lifestyle changes that can help people lower their risk of stroke. Some regular exercise may be one of those changes.
A new study determined that people who are physically active enough to break a sweat four or more times a week may be less likely to have a stroke.
The study found a lowered risk for both men and women who were physically active.
"Get physically active four or more times per week."
Michelle McDonnell, PhD, from the International Centre for Allied Health Evidence at the University of South Australia, and colleagues conducted this study to look at the connection between physical activity and stroke incidents.
The researchers recruited 30,239 males and females over the age of 44 years by telephone and mail. The study took place in a region of the Southeastern United States that the researchers called the "Stroke Belt". States included were North Carolina, South Carolina and Georgia.
The study followed the participants from 2003 to 2007. Information about age, sex, race and ethnicity, along with medical history, was collected over the phone. Physical measurements were collected during a home visit.
The researchers defined disease risk factors to include body mass index (a measurement of body fat based on height and weight), smoking status, alcohol use, diabetes and hypertension (chronic high blood pressure). Participants were called every six months to determine whether any stroke incidents had occurred. For any suspected strokes, medical records were obtained.
The participants were asked about how often they were physically active enough to work up a sweat. Participants were asked if their health limited moderate activities, such as moving a table, vacuuming, bowling, golfing and climbing a flight of stairs.
The participants were then divided into groups by level of physical activity:
- No regular physical activity every week (not active group)
- Physically active one to three times a week (slightly active group)
- Physically active four or more times a week (very active group)
The researchers followed the participants for an average of 5.7 years. The study found that the most physically active participants tended to be white males with higher education levels and higher incomes. They also found that the most active participants had a lower body mass index (BMI) and were less likely to have diabetes.
Of the participants, 33 percent reported that they were not physically active.
During the study, 918 stroke incidents were confirmed. The researchers took into account factors like age, sex and race when comparing the connection between physical activity and stroke.
The study found a strong relationship between level of physical activity and stroke incidents. The relationship was measured by a hazard ratio, which is a measure of how often a particular event happens in one group compared to how often it happens in another group.
The hazard ratio for the not active group compared to the very active group was 1.20. The hazard ratio for the slightly active group compared to the very active group was 1.16.
These hazard ratios mean that the inactive people in the study were approximately 20 percent more likely to have a stroke incident than the very active participants. The group that was active one to three times a week was roughly 16 percent more likely to have a stroke incident compared to the very active group.
The researchers found the very active participants had a lower risk for stroke than the not active participants. Being physically active one to three times a week also lowered the risk of stroke, but less than being active four or more times a week.
The study authors said one possible weakness of this study was that they asked participants how often they were physically active enough to work up a sweat. This left out activities such as walking and biking, and underestimated overall amount of physical activity.
The researchers stated that future studies should measure how hard the participants exercise, for how long and how often.
The researchers noted another weakness of the study was that the participants were asked about physical activity at the beginning of the study, but the stroke events happened years later. The researchers stated that it is possible that the participants might have changed their physical activity levels in that time.
It is also possible that some stroke incidents happened without the participants realizing, the authors said. If this occurred, the stroke incidents would not have been recorded in the research and would have been underestimated.
This study was published online July 18 in the journal Stroke.
The research was funded by the National Institute of Neurological Disorders and Stroke, the National Institute of Health and the Department of Health and Human Services. Dr. McDonnell's work is funded by a National Health and Medical Research Council of Australia Fellowship. The other authors reported no conflict of interest.