Unusual sleep patterns may affect our health by disrupting our genes, researchers report. This could have significant implications for shift workers, business travellers and others who work unusual hours.
Results of a study in which researchers delayed participants' sleep cycle indicate that over 97% of rhythmic genes become out of sync with mistimed sleep. "This really explains why we feel so bad during jet lag, or if we have to work irregular shifts," says Dr. Simon Archer.
In their study, senior author Derk-Jan Dijk and Simon Archer placed 22 participants on a 28-hour day in a controlled environment without a natural light-dark cycle. Each day the participants' sleep-wake cycle was delayed by four hours until sleep occurred 12 hours out of sync with their brain clock and in the middle of what would have been their normal daytime. The researchers then collected blood samples to measure the participants' rhythms of gene expression. An analysis of the blood samples indicated widespread disruption to many biological processes.
The research was conducted at the University of Surrey's School of Biosciences and Medicine and published in the journal Proceedings of the National Academy of Sciences.
These findings add to a growing body of research on potential shiftwork hazards. In July 2012, the British Medical Journal published a report of Canadian research showing a link between shiftwork, heart attacks and strokes. Researchers led by Daniel Hackam, a clinical pharmacologist at the Stroke Prevention & Atherosclerosis Research Centre in London, ON, conducted the largest synthesis of shift work and vascular risk reported to date, involving 34 studies and 2,011,935 people.
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