As men and women enter their golden years, those who regularly fail to get a good night's sleep face a higher risk for developing not one but two serious chronic illnesses at the same time, new research shows.
Researchers from France, Finland and United Kingdom tracked the self-reported sleep routines and health status of nearly 8,000 Britons from ages 50 to 70.
While the new analysis can't prove cause and effect, "the breadth of observational and interventional studies are strongly suggestive of inadequate sleep compromising good health," concluded Dr. Virend Somers, who reviewed the findings. He's a professor of cardiovascular medicine at the Mayo Clinic College of Medicine in Rochester, Minn.
For the study, researchers first looked at how much sleep study participants were getting back in 1985, when they were 50 years old and disease-free.
At the time about 4 in 10 reported regularly getting fewer than seven hours sleep a night, with nearly a third getting five hours or less.
For most people, seven hours is the minimum needed for a healthy night of sleep, said lead author Séverine Sabia, a research associate with the National Institute of Health and Medical Research (Inserm) at the University of Paris.
Her team then looked at which participants were routinely sleeping no more than five hours a night as they entered their 60s and 70s.
And at each milestone, regularly sleeping those fewer hours was linked to a 30% to 40% higher risk of developing multiple illnesses, compared to regularly clocking seven hours a night.
Included among the list of possible illnesses were diabetes, cancer, coronary heart disease, stroke, heart failure, chronic obstructive pulmonary disease, chronic kidney disease, liver disease, depression, dementia and a variety of other mental disorders, Parkinson's disease, and arthritis/rheumatoid arthritis.
Notably, those who slept five hours or fewer at age 50 faced a 30% higher risk — compared with good sleepers — for simultaneously developing two of those illnesses. At age 60, poor sleepers saw their relative risk rise by 32%. By 70, the increased risk hit 40%.
Those who failed to get enough shut-eye at age 50 also faced a 25% spike in their risk of early death, largely because of an increased risk for getting sick, researchers found.
Sabia acknowledged that it's possible that poor sleep could be a function of disease, rather than the cause. But she expressed confidence that her team "used a comprehensive approach to reduce the risk that the findings reflect the impact of the disease on sleep duration."
Adam Krause, doctoral candidate in cognitive neuroscience at the Center for Human Sleep Science at the University of California, Berkeley, said the study makes sense.
"These findings are not too surprising, in showing that short sleep can predict higher incidence of chronic disease later in life," Krause said. "Sleep processes touch every system of the body, so a lack of sleep, especially when experienced long-term, will impact multiple systems whose chronic dysregulation can lead to the development of these common chronic diseases."
As for limiting one's risk of disease, Sabia emphasized the importance of trying to maintain "good sleep hygiene."
That, she said, generally "includes a comfortable bedroom, being physically active and exposed to light during the day, having a sleep routine, avoid screen time and reduce light in the 30 minutes before sleep."
Somers offered one more important tip.
"If there is any likelihood of a sleep disorder -- such as disruptive snoring, sleep apnea or insomnia — it would be helpful to be evaluated and treated by a sleep physician," he said.
The findings were published Oct. 18 in the journal PLOS Medicine.