Stroke is the major cause of disability and mortality at older ages, so preventive strategies are important Physical activity (PA) in middle age is protective against stroke.
Some studies suggest that PA may be more protective against stroke at older ages than in middle age. Walking is a predominant form of PA in older adults. It is therefore important to understand whether and how walking is related to onset of stroke in older adult populations, which have high risks of stroke and low activity levels.
Even though slower walking speeds and less time spent walking are linked to higher total cardiovascular disease mortality risk, few studies of stroke have examined the relative importance of pace in comparison to time spent walking or walking distance.
Dr. Barbara J Jefferis, MSc, PhD, Department of Primary Care and Population Health and Physical Activity Research Group, University College London, UK, and colleagues examined how walking was linked to the onset of stroke in older adult populations with a high risk of stroke and low PA levels.
The study included 3,435 healthy men, aged 60 to 79 years, that were from the British Regional Heart Study, and were followed an average for 11 years. Men self-reported usual pattern of PA; regular daily walking or cycling, recreational activity, and sporting (vigorous) activity. Men reported usual walking during an average week; duration of walking, total number of miles walked, and pace; slow, steady average, fairly brisk and fast (over 4mph). Men also reported recreational and sporting activity. For example, recreational activity included gardening, hiking, and do-it-yourself jobs. Sporting activity included running, golf, swimming and tennis.
Nurses measured the participant’s height, weight, blood pressure and forced expiratory volume in one second and recorded ECG including resting heart rate. Fasting blood samples were collected and analyzed for total and high-density lipoprotein-cholesterol, triglyceride and vitamin C.
Among the participants, 195 first strokes occurred during 11-year follow-up. Men walked on average seven hours a week, walking more hours was associated with lower heart rate, D-dimer, and higher forced expiratory volume in 1 second.
In comparison to men who walked zero to three hours a week, men who walked eight to 14 hours a week had a one-third reduced risk of stroke and those who had walked 22 hours or more saw a reduction in stroke risk by two-thirds.
This study showed that time spent walking was linked to reduced risk of stroke and not walking pace.
The researchers found that established stroke risk factors that included BP and lipids were weak mediators of the link between time spent walking and stroke as were markers of inflammation, coagulation, and cardiac injury.
In their conclusion the researchers write “Time spent walking was associated with reduced risk of onset of stroke in dose–response fashion, independent of walking pace. Walking could form an important part of stroke-prevention strategies in older people.”
Future studies with objective PA measures may clarify the shape of the dose–response curve between activity volume and intensity (including sedentary behavior) and stroke risk better than self-report, which may be subject to recall bias, yet self-reports are required for identifying activity types.
The researchers notes their study only examines men and therefore, cannot generalize results to older women however, one meta-analysis that appeared in the Journal of Women’s Health had concluded that more vigorous PA may be required for protection against stroke in women than men, but this may be because population levels of PA are lower in women than men.
This study appears in the journal Stroke
Each year nearly 800,000 Americans experience a new or recurrent stroke, which is the leading cause of serious, long-term disability in the United States, with about 6.5 million stroke survivors alive today.
To find your risk of having a stroke a stroke risk calculator can be used to assess your risk of having a stroke within the next 10 years.