It's not just about how much sleep you get — when you go to sleep, and whether that time changes based on the day of the week, could have an impact on your health.
Routinely changing when you go to sleep and wake up could raise your risk of health problems like heart disease and diabetes, a new study found.
That's bad news for you if you live for the weekend, adjusting your sleep schedule around late nights out or Netflix binges. This phenomenon is called social jet lag. It's when your actual sleep schedule is out of sync with your body's internal sleep clock, or circadian rhythm, according to lead study author Patricia M. Wong, MS, of the Department of Psychology at the University of Pittsburgh, in a press release.
Dr. Robert S. Rosenberg, board-certified sleep medicine physician and author of "Sleep Soundly Every Night, Feel Fantastic Every Day," told dailyRx News circadian rhythms control a lot of what goes on in our bodies.
"Numerous functions, such as the secretion of insulin, the metabolism and storage of fat, food absorption and cholesterol metabolism, heart rate and blood pressure, are driven by our individual circadian rhythms," Dr. Rosenberg, who was not involved with the current study, said. "When our sleep-wake schedule, because of work and other obligations, is out of phase with our intrinsic circadian clock, this malalignment results in significant untoward metabolic and cardiovascular consequences."
And the current study is the first to clearly show that social jet lag — even being off by as little as 45 minutes — can harm your health, Dr. Rosenberg added.
But what is the average full-time worker supposed to do when she has to get up early for work? Dr. Rosenberg provided some advice.
"Try to stick to a bedtime on weekends that does not differ too much from the workday," he said. "Expose yourself to bright light upon awakening on Monday. This will help to reset your circadian timing to an earlier bedtime Monday night. Avail yourself of as much light as possible at work. If weather permits, eat lunch or take your break outside. Exercise regularly and avoid late-night caffeine and alcohol. Finally, turn off all sources of blue light, such as computers, iPads, cellphones, 60 to 90 minutes before bedtime. You are then much more likely to be able to fall asleep earlier."
To conduct their study, Wong and colleagues looked at 447 patients between the ages of 30 and 54 who worked outside their homes at least 25 hours a week. For a week, patients wore a wristband device that measured their sleep and movements. Nearly 85 percent of these patients showed changes in their sleep patterns between weekdays and weekends, suggesting social jet lag.
The greater the degree of social jet lag patients displayed, the greater their chances of having risk factors for heart disease and diabetes. These risk factors included high insulin levels, bigger waist circumferences, higher body mass index and worse cholesterol measurements, among other factors.
This study was published online Nov. 18 in the Journal of Clinical Endocrinology & Metabolism.
A grant from the National Institutes of Health funded this research. The study authors disclosed no conflicts of interest.