Too much sedentary time can increase long-term stroke risk, researchers say

Calgary, Alberta — If you’re younger than 60 and spend much of your leisure time being inactive, you may be at increased risk of a future stroke, according to a team of Canadian researchers.

Using 2000-2012 data from the Canadian Community Health Survey, the researchers reviewed the health and lifestyles of more than 143,000 participants with no prior stroke, heart disease or cancer.

During follow-ups, conducted on average for 9.5 years, nearly 3,000 participants suffered a stroke. About 90% of the cases were ischemic strokes, which are the most common and occur when a blood vessel to the brain becomes obstructed, according to an American Heart Association press release.

To gauge the participants’ risk, the researchers divided them into four categories based on time spent each day in sedentary activities. Results show that the participants younger than 60 who had low physical activity and reported eight or more hours of sedentary time a day had a 4.2 times greater risk of stroke compared with those who were sedentary for four hours or less. In addition, the most inactive group – those who reported eight or more hours of sedentary time and low physical activity – had a seven times higher risk compared with those who reported less than four hours of sedentary time a day and higher levels of physical activity.

AHA recommends adults get 150 minutes of moderate-intensity activity a week. Boosting weekly physical activity time, the researchers say, can help reduce or eliminate the increased stroke risk from prolonged sedentary time.

“Physical activity has a very important role in that it reduces the actual time spent sedentary, and it also seems to diminish the negative impact of excess sedentary time,” study author and physician Raed Joundi, a stroke fellow in the department of clinical neurosciences at the University of Calgary, said in the release. “Physician recommendations and public health policies should emphasize increased physical activity and lower sedentary time among young adults in combination with other healthy habits to lower the risks of cardiovascular events and stroke.”

The study was published online in Stroke, a journal of the American Stroke Association – a division of AHA.