Most of us live a busy life, waking up, rushing to get ready, and making our way to work. But most of us also stay up later than we should, perhaps to finish watching that movie well past midnight, or maybe you are catching up on housework while reading until you notice it is 1 AM. Around one-third of Americans are in the same situation and habitually get only 5-6 hours of sleep falling short of the recommended 7-8 hours of sleep per night.
It may not seem like a lot, but it all adds up, and even mild chronic sleep deficits may increase the risk of developing heart disease later in life according to research: thousands of people who report mild but chronic sleep deficits have been found to have more heart disease later in life than those who get adequate sleep. A recent study from the Columbia University Irving Medical Center shows what is happening in the body during chronic mild sleep deprivation.
“This is some of the first direct evidence to show that mild chronic sleep deficits cause heart disease,” says study leader Sanja Jelic, MD, director of the Center for Sleep Medicine at Columbia and professor of medicine in the Division of Pulmonary, Allergy, and Critical Care Medicine at Columbia University Vagelos College of Physicians and Surgeons.”Until now we’ve only seen associations between sleep and heart health in epidemiological studies, but these studies could be tainted by many confounders that cannot be identified and adjusted for. Only randomized controlled studies can determine if this connection is real and what changes in the body caused by short sleep could increase heart disease.”
This study screened close to 1,000 women enrolled in the Washington Heights Study, enrolling 35 healthy women who normally slept 7-8 hours per night to participate in this 12-week study. Wearing wrist-worn sleep trackers, for 6 weeks the women kept their usual sleep routine, then went to bed 1.5 hours later than normal for the following 6 weeks.
The study found that after only 6 weeks of shortened sleep the cells that line our blood vessels become flooded by damaging oxidants, and the sleep-restricted cells fail to activate antioxidant responses to clear the destructive molecules, unlike their well-rested counterparts. This results in cells that are inflamed and dysfunctional, which is an early step towards the development of cardiovascular disease.
Previous research did not examine chronic sleep deficits. In the past studies of human sleep have largely only examined the physiological effects of a few nights of profound sleep deprivation.
“But that’s not how people behave night after night. Most people get up around the same time each day but tend to push back their bedtime one to two hours,” Jelic says. “We wanted to mimic that behavior, which is the most common sleep pattern we see in adults.”
“Many problems could be solved if people sleep at least seven to eight hours per night,” Jelic says. “People who are young and healthy need to know that if they keep getting less sleep than that, they’re aggravating their cardiovascular risk.”
