Not catching enough Z’s or having a sleep disorder can affect cardiovascular health and risk, says the first-ever scientific statement about sleep from the American Heart Association.
Sleep disorders are “very much” related to cardiovascular disease, said Marie-Pierre St-Onge, Ph.D., an associate professor of nutritional medicine at Columbia University in New York City who chaired the panel that wrote the statement, released Monday. “How [people] choose to spend their nighttime hours is very important to their health.”
Researchers found that sleep issues, especially not sleeping enough, obstructive sleep apnea and insomnia can influence the risk of obesity, high blood pressure, Type 2 diabetes, stroke, coronary heart disease and overall cardiovascular disease.
More than one in three U.S. adults do not get enough sleep, according to the Centers for Disease Control and Prevention. The National Institutes of Health’s National Center on Sleep Disorders Research estimates that sleep disorders, sleep deprivation and sleepiness cost the U.S. healthcare system about $15.9 billion a year.
“It’s fabulous that sleep is getting attention,” said Nancy Collop, M.D., a professor of medicine and neurology and director of the Emory Sleep Center in Atlanta.
Sleep helps to regenerate body tissue and cements the previous day’s memories in the brain, she said. But assessing it can be difficult because of its objective and subjective components.
A good night’s sleep allows someone to wake up and go through the next day’s activities without being sleepy or tired, Collop said. “If you’re not sleeping well, it can affect your job, interaction with your family and your overall health.”
Despite debate among sleep experts about the optimal number of hours needed per night, Collop’s experience with her own patients indicates most adults need seven hours of quality sleep, but others may need more or less.
More Americans have been shortchanging their sleep in recent decades. The proportion getting less than seven hours of shut-eye a night rose from about 22 percent in 1977 to 29 percent in 2009, the statement said.
“I’m always amazed at how little people think they need to sleep,” Collop said. “People are more aware of healthy eating and exercise, but they’re leading busy lives so what they give up first is sleep.”
So-called “short sleepers” are more likely to gain weight than normal sleepers, St-Onge said. Studies show that sleep-deprived people eat more, especially high-fat foods and snacks.
“It’s a vicious cycle. I think that sleep can influence diet and physical activity level in such a way that leads to an increased risk of obesity,” she said. “Once you’ve reached overweight and obesity, you’re increasing your risk of sleep disorders.”
According to the statement, the risk of dying from coronary heart disease is higher for those getting less than seven hours or more than nine hours of sleep, or taking certain sleep medications.
Lack of sleep is only one of the conditions affecting cardiovascular health.
Insomnia and sleep apnea are the most common sleep disorders, although the vast majority of people with insomnia are never diagnosed, according to the statement.
Insomnia occurs when someone has difficulty falling asleep or staying asleep at least three nights a week for at least three months. Sleep apnea is diagnosed as five or more pauses in breathing per hour of sleep, most commonly due to a narrowed airway. The pauses can last seconds or minutes.
According to the statement, more large-scale research is needed to determine whether extending sleep or treating insomnia can reduce cardiovascular risks.
Most sleep and cardiovascular disease research has been limited to smaller, short-term studies, St-Onge said. She’s interested in research looking at the direct effects of sleep issues on cardiovascular health, and strategies to effectively treat sleep problems long-term.
“Heart disease doesn’t develop overnight,” she said.
Despite many unknowns about sleep, experts are learning “more and more” about what it does for the body, Collop said. Some of this has been driven by patients asking their doctors more questions, she said.
St-Onge hopes Americans and their doctors pay more attention to sleep.
“I would hope that doctors start talking to their patients about their sleep as part of their routine care, as they do, or should do, with physical activity and diet,” she said. Doctors should also ask about snoring and fatigue, she said, and refer patients for further testing if needed.
Sleep is important and “not something that can be dismissed without dire consequences,” St-Onge said.