26 Jul Stroke Risk and Physical Activity Frequency
MedicalResearch.com: What are the main findings of the study?
Dr. McDonnell: In this study, we asked people how many times a week they engaged in intense physical activity, enough to work up a sweat. People responded that they were physically active 0, 1-3 or 4 or more times a week. When we followed up these people for several years, those who did not do any vigorous exercise were 20% more likely to have a stroke, compared to those who exercised four or more times a week. However, when we adjusted these results for other risk factors, this attenuated the effect down to 14% which was not statistically significant. We also noticed that people who exercised four or more times a week had less hypertension (high blood pressure), were less likely to be obese and less likely to have diabetes. Each of these things on their own reduces your risk of stroke, so when we adjust for that the association between physical activity and stroke is weaker (20% to 14%). So physical activity seems to have an effect on stroke risk by improving these other risk factors.
MedicalResearch.com: Were any of the findings unexpected?
Dr. McDonnell: As we expected, those who were more physically active were less likely to have hypertension (high blood pressure), a high body mass index and less likely to have diabetes. The unexpected finding was that this group was also more likely to report heavy alcohol use, which was defined as ≥7 drinks/wk for women and ≥14 drinks/wk for men.
MedicalResearch.com: What should clinicians and patients take away from your report?
Dr. McDonnell: I think the big message here is that you can control your destiny with regards to stroke. It is largely preventable, and many people don’t know that they can change their risk of stroke by adhering to some healthy lifestyle choices. A combination of healthy diet, healthy body weight, regular exercise along with a moderate alcohol consumption and not smoking can reduce your risk of stroke by 80%.
Here we show that regular physical activity is an important aspect of that, and should be encouraged. And it is quite a simple message for clinicians: Ask your patients whether they are physically active four or more times a week at an intensity to work up a sweat. Let them know that this level of physical activity is good for their health for many reasons, but particularly to reduce their risk of stroke.
MedicalResearch.com: What recommendations do you have for future research as a result of this study?
Dr. McDonnell: Much more research needs to be done to quantify just how much of a benefit you receive from exercise to reduce stroke risk according to how much exercise you do. Just like we know the dose of medication you need to take to reduce blood pressure, we would like to clarify the effect of precise amounts of exercise on improving your health outcomes.
Physical Activity Frequency and Risk of Incident Stroke in a National US Study of Blacks and Whites
Michelle N. McDonnell, Susan L. Hillier, Steven P. Hooker, Anh Le, Suzanne E. Judd, and Virginia J. Howard
Stroke. 2013;STROKEAHA.113.001538published online before print July 18 2013, doi:10.1161/STROKEAHA.113.001538