CHICAGO --- Having trouble falling or staying asleep may leave you feeling tired and frustrated. It also could subtract years from your life expectancy, according to a new study from Northwestern Medicine and the University of Surrey in the United Kingdom (UK).
The effect was even greater for people with diabetes who experienced sleep disturbances, the study found. Study participants with diabetes who experienced frequent sleep disturbances were 87% more likely to die of any cause (car accident, heart attack, etc.) during the 8.9-year study follow-up period compared to people without diabetes or sleep disturbances. They were 12% more likely to die over this period than those who had diabetes but not frequent sleep disturbances.
"If you don't have diabetes, your sleep disturbances are still associated with an increased risk of dying, but it's higher for those with diabetes," said corresponding study author Kristen Knutson, associate professor of neurology (sleep medicine) and preventive medicine (epidemiology) at Northwestern University Feinberg School of Medicine.
But by answering one simple question -- "Do you have trouble falling asleep at night or do you wake up in the middle of the night?" -- people can begin to address sleep disturbances earlier in life and hopefully mitigate this increased risk of death, Knutson said.
"This simple question is a pretty easy one for a clinician to ask. You can even ask yourself," Knutson said. "But it's a very broad question and there are a lot of reasons you might not be sleeping well. So it's important to bring it up with your doctor so they can dive deeper.
"Is it just noise or light or something bigger, like insomnia or sleep apnea? Those are the more vulnerable patients in need of support, therapy and investigation into their disease."
The study will be published June 8 in the Journal of Sleep Research.
"Although we already knew that there is a strong link between poor sleep and poor health, this illustrates the problem starkly," said first study author Malcolm von Schantz, professor of chronobiology from the University of Surrey. "The question asked when the participants enrolled does not necessarily distinguish between insomnia and other sleep disorders, such as sleep apnea. Still, from a practical point of view it doesn't matter. Doctors should take sleep problems as seriously as other risk factors and work with their patients on reducing and mitigating their overall risk."
The authors analyzed existing data of nearly half a million middle-aged participants in the UK Biobank Study. To the scientists' knowledge, it is the first study to examine the effect of the combination of insomnia and diabetes on mortality risk.
"We wanted to see if you have both diabetes and sleep disturbances, are you worse off than just diabetes alone?" Knutson said. "It could have gone either way, but it turns out having both diabetes and sleep disturbances was associated increased mortality, even compared to those with diabetes without sleep disturbances."
Participants had predominately Type 2 diabetes, the most prevalent form, though some had Type 1.
Jason Ong, adjunct associate professor of neurology (sleep medicine) at Feinberg is a co-author on the study.
The study was supported by funding from the U.S. National Institutes of Health (grant numbers R01DK095207 and 1R01HL141881) and by a University of Surrey Institute of Advanced Studies Santander fellowship.
Journal of Sleep Research