Getting good sleep could add years to your life

"We saw a clear dose-response relationship, so the more beneficial factors someone has in terms of having higher quality of sleep, they also have a stepwise lowering of all cause and cardiovascular mortality," said Frank Qian, MD, an internal medicine resident physician at Beth Israel Deaconess

Medical Center, clinical fellow in medicine at Harvard Medical School and co-author of the study. "I think these findings emphasize that just getting enough hours of sleep isn't sufficient. You really have to have restful sleep and not have much trouble falling and staying asleep."

For their analysis, Qian and team included data from 172,321 people (average age 50 and 54% women) who participated in the National Health Interview Survey between 2013 and 2018. This survey is fielded each year by the Centers for Disease Control and Prevention (CDC) and the National Center for Health Statistics to help gauge the health of the U.S. population and includes questions about sleep and sleep habits. Qian said this is the first study to his knowledge to use a nationally representative population to look at how several sleep behaviors, and not just sleep duration, might influence life expectancy.

About two-thirds of study participants self-reported as being White, 14.5% Hispanic, 12.6% Black and 5.5% Asian. Because researchers were able to link participants to the National Death Index records (through December 31, 2019), they could examine the association between individual and combined sleep factors and all-cause and cause-specific mortality. Participants were followed for a median of 4.3 years during which time 8,681 individuals died. Of these deaths, 2,610 deaths (30%) were from cardiovascular disease, 2,052 (24%) were from cancer and 4,019 (46%) were due to other causes.

Researchers assessed ?ve different factors of quality sleep using a low-risk sleep score they created based on answers collected as part of the survey. Factors included: 1) ideal sleep duration of seven to eight hours a night; 2) difficulty falling asleep no more than two times a week; 3) trouble staying asleep no more than two times a week; 4) not using any sleep medication; and 5) feeling well rested after waking up at least five days a week. Each factor was assigned zero or one point for each, for a maximum of five points, which indicated the highest quality sleep.

"If people have all these ideal sleep behaviors, they are more likely to live longer," Qian said. "So, if we can improve sleep overall, and identifying sleep disorders is especially important, we may be able to prevent some of this premature mortality."

For the analysis, researchers controlled for other factors that may have heightened the risk of dying, including lower socioeconomic status, smoking and alcohol consumption and other medical conditions. Compared to individuals who had zero to one favorable sleep factors, those who had all five were 30% less likely to die for any reason, 21% less likely to die from cardiovascular disease, 19% less likely to die from cancer, and 40% less likely to die of causes other than heart disease or cancer. Qian said these other deaths are likely due to accidents, infections or neurodegenerative diseases, such as dementia and Parkinson's disease, but more research is needed.

Among men and women who reported having all five quality sleep measures (a score of five), life expectancy was 4.7 years greater for men and 2.4 years greater for women compared with those who had none or only one of the five favorable elements of low-risk sleep. More research is needed to determine why men with all five low-risk sleep factors had double the increase in life expectancy compared with women who had the same quality sleep.

"Even from a young age, if people can develop these good sleep habits of getting enough sleep, making sure they are sleeping without too many distractions and have good sleep hygiene overall, it can greatly benefit their overall long-term health," Qian said, adding that for the present analysis they estimated gains in life expectancy starting at age 30, but the model can be used to predict gains at older ages too. "It's important for younger people to understand that a lot of health behaviors are cumulative over time. Just like we like to say, 'it's never too late to exercise or stop smoking,' it's also never too early. And we should be talking about and assessing sleep more often."

These sleep habits can be easily asked about during clinical encounters, and the researchers hope patients and clinicians will start talking about sleep as part of their overall health assessment and disease management planning.

One limitation of the study is that sleep habits were self-reported and not objectively measured or verified. In addition, no information was available about the types of sleep aid or medicine used or how often or long participants used them. Future research is needed to understand how these gains in life expectancy might continue as people age, as well as further explore the sex differences that were observed.

Previous studies have shown that getting too little or too much sleep can negatively affect the heart. It's also been widely reported that sleep apnea, a sleep disorder that causes someone to pause or stop breathing while asleep, can lead to a number of heart conditions, including high blood pressure, atrial fibrillation and heart attacks.