Shift to daylight saving time comes with a few risks
The one-hour shift, with its slight alteration of sleep routines, comes with a few risks documented by researchers.
Start with the heart.
A risk of a heart attack increases significantly for the first three weekdays after the transition to daylight saving time, according to a study published in the New England Journal of Medicine.
“Falling back,” with the extra hour of sleep attending the autumn transition away from daylight saving time, is apt to significantly increase the risk of heart attack on the first weekday, the study found.
Another study, published by the American Journal of Cardiology, concluded that the shifts to and from daylight saving time might “transiently” increase the risk of “acute cardiac events,” although modestly.
Dr. Seema Khosla, an internal medicine physician and sleep specialist, said many people already suffer from chronic sleep deprivation, which could make them more vulnerable to the abrupt change daylight saving time brings.
“Maybe this is just that little trigger that will precipitate that event,” said Khosla, medical director of the North Dakota Center for Sleep in Fargo.
Insufficient sleep by itself has been linked to elevated stress hormones, and increased risks of cardiovascular disease, obesity and high blood pressure, among other health problems, she said.
“To me it seems reasonable” that shifting to daylight saving time could exacerbate health problems people already are prone to having, she added. “I think it’s a host of events.”
Dr. Stephanie Hanson, a pediatrician at Sanford Health, agrees insufficient sleep can increase health risks and said the increase in stress hormones is well documented, along with high blood pressure, mood changes and depression.
“So I think the risk is real,” she said of daylight saving time shifts.
Unfortunately, Hanson added, few people think ahead and prepare for the time change.
“I think very few people plan ahead for this transition,” Hanson said. She recommends going to bed a little early for several days ahead of the switch to ease the adjustment.
“I hear a lot of people complaining about it,” Hanson said of the lost hour of sleep from “springing ahead.” “But nobody asks proactively what to do about it.”
The slight disruptions in sleep patterns could also increase the risk of traffic accidents, researchers have found. Similarly, other accidents, including those in the workplace, and school performance might suffer, though some research findings are mixed.
Studies have disagreed about whether car accidents increase from daylight saving time. One Canadian researcher has suggested accidents increase because mornings are darker, especially when the time shift starts.
Mine workers came to work with 40 minutes less sleep and experienced 5.7 percent more work-site injuries in the days following the springtime daylight saving time transition, a study in the Journal of Applied Psychology found. Researchers attributed the injuries to lack of sleep.
Productivity on the job might take a hit, too. Time spent “cyberloafing” — surfing the Internet while at work — increased the first Monday after daylight saving time in the spring, according to a study in the Journal of Applied Psychology.
The seemingly slight one-hour shift in the sleep cycle can alter sleep for up to a week, according to a report in the journal Sleep Medicine Reviews.
Disruptions in sleep patterns can upset the routine physical and behavioral variations during a day. These are called circadian rhythms and can be affected by outside influences, including light or daylight saving time.
An Australian study, which analyzed four decades of suicide data, found elevated suicide rates in the weeks following the end of daylight saving time.
That suggests that small changes in the body’s circadian rhythms and biological clock can be destabilizing for vulnerable people, concluded the authors of the study, published in the journal Sleep and Biological Rhythms. Big shifts are known to cause problems with people who have bipolar disorder.
Medical professionals recommend that people establish and maintain routine sleep patterns, consistently going to bed and waking at the same time.
Parents should keep televisions out of their children’s bedrooms and restrict “screen time” before bedtime, Hanson said.
“People don’t always do a lot of limit-setting for their children,” Hanson said.
Despite the disruption, and associated health risks, Hanson and Khosla are fans of daylight saving time.
“I like having that extra hour of daylight at springtime,” Hanson said.