That’s because people with high blood pressure or diabetes — two of the main risk factors for heart attack and stroke — are more than twice as likely to die from these cardiovascular events when they sleep less than six hours a night. And once people have already had a heart attack or stroke, they’re more than 3 times as likely to die from cancer when they sleep less than six hours a night. The good news, though, is that people who get at least six hours of sleep don’t appear to be at an increased risk of early death from cancer or other causes, even when they have diabetes, high blood pressure, or a history of heart attack or stroke. “Our study suggests that achieving normal sleep may be protective for some people with these health conditions and risks,” says Julio Fernandez-Mendoza, PhD, lead study author and a sleep psychologist at the Sleep Research & Treatment Center of the Penn State Health Milton S. Hershey Medical Center in Hershey, Pennsylvania. “However, further research is needed to examine whether improving and increasing sleep through medical or behavioral therapies can reduce the risk of early death,” Dr. Fernandez-Mendoza adds. RELATED: How Doctors Diagnose Sleep Apnea — and What to Expect at a Sleep Study
Too Little Sleep Increases Stress
Roughly 1 in 3 people report getting too little sleep, and previous studies that objectively measured sleep in lab tests have found that about one-half of adults get less than six hours of shut-eye a night, the study team noted. At the start of the current study, researchers asked 1,654 adults who were 48 years old years old on average to spend one night in a sleep lab. Overall, participants got an average of 5.9 hours of sleep that night, and 44 percent of them got less than six hours. Sleep outcomes were worse among the subset of 1,060 people who had diabetes, hypertension, or a previous heart attack or stroke. In this group, people got an average of just 5.6 hours of sleep in the lab, and 55 percent of them got less than six hours. After about 19 years of follow-up, a total of 512 participants, or about 31 percent, died. This included 209 individuals who died of events like heart attacks or strokes as well as 131 cancer fatalities. The study wasn’t a controlled experiment designed to prove whether or how sleep duration might directly impact longevity, or how getting more rest might help people live longer. One limitation of the study is that sleep duration was based on observing just a single night in the lab, researchers note. It’s possible participants slept worse than usual that first night in a strange bed and that their sleep would look better if it was assessed over several consecutive nights. Even so, the results offer fresh evidence that sleep is one key to a longer life, says Marie-Pierre St-Onge, PhD, director of the Sleep Center of Excellence at Columbia University Irving Medical Center in New York City. “Too little sleep suppresses our immune system and places our body in a state of heightened alertness for stressful events like a fight-or-flight mode,” says Dr. St-Onge, who wasn’t involved in the study. “Such processes contribute to the development of cardiovascular and cerebrovascular disease,” St-Onge adds. “It’s possible that putting our body in this vulnerable state can accelerate the progression of cerebrovascular disease and cancers.” Adults 18 to 60 years old should get at least seven hours of sleep a night, according to the U.S. Centers for Disease Control and Prevention (CDC). This is easier to achieve when you go to bed at the same time each night and wake up at the same time each morning, including weekends. Sleeping in a dark, quiet, relaxing room at a comfortable temperature also helps, according to the CDC. It’s also a good idea to avoid large meals, caffeine, and alcohol before bedtime, and get some exercise every day.
