Stroke is a brain injury caused by an interruption in blood flow. It is a leading cause of death in the US, and can also cause disability, decreased quality of life, and increased healthcare expenses. There are many lifestyle factors that affect you risk of stroke including diet, exercise, smoking, and stress. Other lifestyle habits like long periods of standing or long work hours are also being reviewed for their impact on stroke risk.
Earlier research has suggested that long working hours may be linked to stroke, but the evidence is limited. Researchers wanted to determine if there was a possible connection between long work hours and the risk of stroke. The study, published in Lancet, found that employees who work long hours have a higher risk of stroke than those who do not.
The systematic review of observational studies included 528,908 men and women from Europe, the US, and Australia who were free from history of stroke at the beginning of the study. The participants volunteered their work hours and were tracked for the development of stroke. During an average 7.2 year follow up there were 1,722 stroke-related events.
Compared to those who worked standard hours (35-40 hours/week), participants who worked 49-54 and more than 55 hours a week had an increased risk of stroke.
The effects remained apparent even when other stroke factors like age, sex, and health history were accounted for.
A systematic review pools a large number of trials to create a larger pool of data. The larger the pool of data, the more reliable outcomes are. However, the review is only as reliable as the trials that are included. The included studies were all observational studies which means a direct cause and effect link could not be established and the studies can only show a potential link between factors.
There is a reasonable link between extra work hours and stroke since longer hours are often associated with extra stress and less relaxation time. If you have long work hours, you may want to talk to your doctor about your personal risk factors for stroke and follow other stroke prevention methods, such as:
Family Doctor—American Academy of Family Physicians
American Stroke Association
Kivimäki M, Jokela M, et al. Long working hours and risk of coronary heart disease and stroke: a systematic review and meta-analysis of published and unpublished data for 603,838 individuals. Lancet. 2015 Oct 31;386(10005):1739-1746. Available at: http://www.thelancet.com/journals/lancet/article/PIIS0140-6736%2815%2960295-1/fulltext. Accessed January 19, 2016.
Risk factors for stroke or transient ischemic attack. EBSCO DynaMed website. Available at: http://www.ebscohost.com/dynamed. Updated December 28, 2015. Accessed January 19, 2016.
Last reviewed January 2016 by Michael Woods, MD