Does Changing the Clock Increase Risk of Stroke?


Falling back may have more of an impact on your health than you realize.

A study released last year at the American Academy of Neurology’s annual meeting found daylight saving time transitions may be tied to a temporary increase in the risk of ischemic stroke.

Ischemic stroke is the most common kind of stroke, accounting for 87 percent of all cases. It is caused by a clot blocking blood flow to the brain.

Previous research has shown that disruptions in a person’s circadian rhythm, or internal body clock, increase the risk of stroke. To see whether daylight saving time puts people at risk, researchers in Finland looked at a decade of data that compared the rate of stroke in 3,033 people hospitalized during the week following a daylight saving time transition to the rate of stroke in a group of 11,801 people hospitalized either two weeks before or two weeks after that week.

Researchers found that the overall rate of ischemic stroke was 8 percent higher during the first two days after a daylight saving time transition than at other times. The risk of stroke during the week following a seasonal time change was particularly high for certain groups of people. People with cancer were 25 percent more likely to have a stroke following a time change and people over the age of 65 were 20 percent more likely.

Further research is needed to establish whether there is a significant correlation between circadian rhythms and stroke risk, specifically during daylight savings time transitions, says Dr. Lindsay Pattison of St. Elizabeth Physicians Neurology.

In the meantime, she said, individuals should focus on stroke risks they can mitigate through lifestyle adjustments. “These include working with your primary care physician on tight blood pressure, blood sugar, and cholesterol control.  Smoking cessation and treatment of underlying obstructive sleep apnea are also recommended. A balanced, healthy diet and regular physical activity will help to reduce your stroke risk as well as improve your overall health.”

Don’t forget to switch your clocks this Sunday, November 5!

Learn more about your stroke risk through a simple, painless screening of your neck arteries on the St. Elizabeth CardioVascular Mobile Health Unit. Plaque buildup in these arteries is one of the leading causes of stroke. Click here to see upcoming screening dates and locations.