Research shows shift work can lead to severe strokes

Shift works unwinds body clocks and leads to more severe strokes, according to a release issued by Texas A&M Health Science Center Office of Public Affairs.

Statistics show that around 15 million Americans do not work the typical nine-to-five shift, and according to the release new research published in Endocrinology states that employees or shift workers who works rotating shifts are more prone to numerous health hazards, including heart attacks and obesity. Shift work can also cause other serious implications on the brain.

“The body is synchronized to night and day by circadian rhythms, or a 24-hour cycle controlled by internal biological clocks that tell our bodies when to sleep, when to eat and when to perform numerous physiological processes,” said David Earnest, professor in the Department of Neuroscience and Experimental Therapeutics at the Texas A&M Health Science Center College of Medicine. “A person on a shift work schedule, especially on rotating shifts, challenges, or confuses, their internal body clocks by having irregular sleep-wake patterns or meal times.”

According to Earnest it is the change in timing of waking, sleeping and eating every few days that makes it difficult for our body-clocks to maintain their natural 24-hour cycle. This can have a major impact on health.

Earnest and his colleagues have discovered, by using an animal model, that shift work can lead to more severe ischemic strokes, where blood flow is cut off to part of the brain, which is also the leading cause of disability in the United States.

Their research, supported by the American Heart Association, also showed that there is a difference between males and females. The gravity of stroke outcomes in response to shift work schedules were much worse in males than in females.

“These sex differences might be related to reproductive hormones. Young women are less likely to suffer strokes, as compared with men of a similar age, and when they do, the stroke outcomes are likely to be less severe. In females, estrogen is thought to be responsible for this greater degree of neuroprotection,” professor in the Department of Neuroscience and Experimental Therrapeutics and director of the Women’s Health in Neuroscience Program, Farida Sohrabji said.

However, “older women approaching menopause show increasing incidence of ischemic stroke and poor prognosis for recovery, compared with men at the same age,” the release said.

“This research has clear implications for shift workers with odd schedules, but probably extends to many of us who keep schedules that differ greatly from day-to-day, especially from weekdays to weekends. These irregular schedules can produce what is know as ‘social jet lag,’ which similarly unwinds our body clocks so they no longer keep accurate time, and thus can lead to the same effects on human health as shift work,” Earnest added.

According to the release this study tells health professionals that shift work-type professions should be monitored more frequently for cardio- and cerebrovascular disease and risk factors such as hypertension and obesity.

In the meantime, Earnest suggest that people with irregular sleeping patterns at least try to eat at regular times and avoid cardiovascular risk factors such as high-fat diet, inactivity and tobacco use.