Using the weekend to catch up on sleep may not be good for heart health, a new study suggests.
The study, presented Tuesday at the American Heart Association's Scientific Sessions, included more than 21,000 older female health care professionals without a history of cardiovascular disease or cancer. Those who spent two or more hours catching up on sleep over the weekend—what researchers call "sleep debt"—were more likely to have poor cardiovascular health.
Sleep expert Marie-Pierre St-Onge, Ph.D., said the findings suggest people who catch up on sleep over the weekend aren't counteracting the harmful effects of not getting enough sleep the rest of the week.
"You're not really salvaging yourself," said St-Onge, an associate professor of nutritional medicine at Columbia University Department of Medicine in New York City, who was not part of the new study.
It's best to get at least seven hours of sleep each night and to go to bed and wake at about the same time every day, she said.
Even after researchers accounted for factors such as income, education and overall stress, women with sleep debt were still worse off.
The news is especially troubling because women are living longer and report more sleep issues than men, said Michelle Albert, M.D., the study's senior researcher and a professor of medicine at the University of California, San Francisco. Women in the study were 72 years old on average.
Between 50 and 70 million U.S. adults don't get enough sleep or have sleep disorders, according to estimates from the National Heart, Lung, and Blood Institute.
Among people with acute coronary syndromes, which includes heart attacks and other sudden blockages of blood flow to the heart, about a third report having sleep disturbances, said Albert. She is the director of UCSF's NURTURE Center, which conducts research related to adversity, social determinants of health and cardiovascular disease.
Previous studies of sleep and cardiovascular disease have mostly focused on the total amount of sleep, not sleep debt, Albert said. A 2016 scientific statement from the American Heart Association reported that not sleeping enough, obstructive sleep apnea and insomnia can influence the risk of obesity, high blood pressure, Type 2 diabetes, stroke and coronary heart disease.
What this latest study adds is more evidence that it's not only important to get enough sleep, but it's also important to not change sleep patterns from weekday to weekend, Albert said.
Sleep deprivation affects levels of the stress hormone cortisol, inflammation and our "fight or flight" hormones, which can increase weight and blood pressure, and contribute to cardiovascular disease, Albert said.
In addition, St-Onge said changing up the sleep routine on the weekends could negatively affect circadian rhythms and affect the sympathetic and parasympathetic nervous system and other factors affecting well-being and longevity.
"People tend to leave all healthy behaviors to the weekend," she said. "We call those people weekend warriors, who hit the gym on the weekend but remain sedentary all week. Healthy behaviors, including healthy eating, exercise, and achieving adequate sleep, should occur throughout the week."
According to Albert, researchers need to learn more about how sleep debt specifically interacts with other sleep disturbances and contributes to poor heart health.
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