The study, published Tuesday in the Journal of Sleep Research, analyzed data from nearly half a million middle-aged participants in the UK Biobank Study, which houses in-depth genetic and health information on UK residents.
After controlling for medical and lifestyle issues that might also affect sleep, such as age, gender, weight, smoking, depression and other preexisting conditions, the study found that people who slept poorly but did not have diabetes were 11% more likely to die within the nine-year followup period of the study than people without diabetes who slept well.
“People with diabetes, but not sleep disturbances, were 67% more likely to die compared to people with neither diabetes or sleep issues, and 87% more likely to die if they had both diabetes and frequent sleep disturbances,” said study author Kristen Knutson, associate professor of neurology and preventive medicine at Northwestern University Feinberg School of Medicine.
Knutson and her team also compared people with diabetes who slept well to people with the condition who often experience poor sleep.
“People with diabetes who slept badly were 12% more likely to die over a nine-year followup period than people with diabetes who slept without frequent sleep disturbances,” Knutson said.
The study is the first to look at the combination of diabetes plus sleep disturbances and mortality risk, she added.
Known link between diabetes and sleep problems
A study of this type can only show association and not causation, said sleep specialist Dr. Raj Dasgupta, an assistant professor of clinical medicine at the Keck School of Medicine at the University of Southern California, who was not involved in the research.
While the study’s findings are disturbing, he said, they are not surprising.
“Diabetes is a deadly disease and it can be easily affected by sleep — or the other way around,” Dasguta said. “Are you getting poor sleep because your diabetes is poorly controlled or is the poor sleep making your diabetes worse?”
For example, Dasgupta said, people with Type 2 diabetes, the most common type, tend to be overweight and may suffer from obstructive sleep apnea, when throat muscles relax and close the airway, thus disrupting sleep.
“People with Type 2 diabetes are also predisposed to kidney issues and make multiple trips to the bathroom in the night because they’re always urinating, especially if their diabetes is poorly controlled,” he added. “They can also have damage to blood vessels which causes leg pain called neuropathy, and It’s hard to go to sleep because of that pain.”
It’s also possible that poor quality sleep may impact the body’s ability to regulate blood sugars, thus contributing to the development of diabetes, Knutson said.
“There’s experimental work which shows that if you take healthy people and disturb their sleep you see impairments in insulin sensitivity,” she said. “There could be a bidirectional association between the two, so if you have sleep issues for a long period of time it may actually lead to the development of diabetes.”
What to do?
Acknowledge and tackle your sleep problems, regardless of whether or not you have diabetes, Knutson said. Sleeping poorly is a risk factor for premature death from any cause all by itself.
“If you usually have trouble falling or staying asleep, you need to talk to a physician and really get at the root of the problem. Find out why aren’t you sleeping well and then figure out how to fix it,” she said.
If you have diabetes, “treat your diabetes — that’s the take home message from this study,” Dasgupta said.”Diabetes is something that needs to be managed by your primary care doctor and endocrinologist.”
If you’re not sleeping well, it may be harder to manage your diabetes, Knutson said.
“It’s not easy to do and then if you’re sleep deprived, maybe you’re just not as good at remembering to take your medication or measure your blood sugars,” she said.
A sleep specialist may also need to do a sleep study to see if you have an underlying sleep disorder, Dasgupta said.
“When you tell me someone’s waking up quite a bit and they have diabetes, I may not only do need to treat the diabetes, I need to treat sleep apnea or restless leg syndrome or another sleep issue,” Dasgupta added. “Don’t hesitate to get the help you need.”