A single, simple question about sleep habits asked to people with diabetes in the UK Biobank database identified a subgroup with a nearly doubled mortality rate during almost 9 years of follow-up: those who said they usually had sleep disturbances.
The question was: Do you never, rarely, sometimes, or usually have trouble falling asleep, or waking in the middle of the night?
Adults in the UK Biobank with any form of self-reported diabetes or insulin use who answered that they usually have sleep disturbances had a significant 87% higher mortality rate than did those without diabetes who said they never or rarely had sleep disturbances, in a fully adjusted model with an average follow-up of 8.9 years, Kristen L. Knutson, PhD, and coauthors reported in the Journal of Sleep Research.
Mortality was 11% higher in respondents who reported frequent sleep disturbances but had no diabetes than in those without frequent sleep disturbances. Furthermore, those with diabetes but without frequent sleep disturbances had a 67% higher mortality rate, compared with those without diabetes. Both differences were statistically significant in a model that adjusted for age, sex, ethnicity, smoking, sleep duration, body mass index, and other covariates.
The findings suggest that diabetes and frequent sleep disturbances act in a roughly additive way to raise mortality risk, said Knutson, an epidemiologist and neurologist who specializes in sleep medicine at Northwestern University, Chicago.
She suggested that, based on these findings, clinicians should consider annually asking patients with diabetes this key question about the frequency of their sleep disturbances. They should then follow up with patients who report usual disturbances by referring them to a sleep clinic to test for a sleep disorders such as insomnia or sleep apnea. Sleep apnea especially is “particularly common in patients with type 2 diabetes,” Knutson noted in an interview.
A Need to ‘ Spread Awareness ‘ About Diabetes and Disturbed Sleep
The study run by Knutson and associates “is one of the largest population-based studies” to examine the relationship between sleep disturbances, diabetes, and mortality, commented Sirimon Reutrakul, MD, an endocrinologist and diabetes specialist at the University of Illinois Hospital in Chicago.
“This study highlights the detrimental effects of sleep disturbances in people with or without diabetes, and adds to the effects of sleep disturbances such as insomnia symptoms. People with diabetes often have sleep disturbances. Obstructive sleep apnea is very common in people with diabetes, and insomnia symptoms could be present in people with obstructive sleep apnea or it could be a separate problem,” Reutrakul said in an interview. Sleep disturbances can arise from direct effects of diabetes, such as nocturia, worry about glucose levels, pain, depressive symptoms, and anxiety, or can result from comorbidities that interfere with sleep.
“It is prudent to ask patients with diabetes about sleep patterns,” said Reutrakul, and she endorsed the specific question that Knutson recommended asking patients. Other aspects of sleep quality that could be helpful for a diagnosis include sleep duration, sleep timing, and snoring. “Some physicians ask these questions, but we need to spread awareness,” she added.
Prior to referring patients to a sleep clinic, Reutrakul suggested that clinicians could also assess possible triggers such as inadequate glucose control, pain, and anxiety, and they could also recommend good sleep hygiene strategies such as what’s recommended by the Sleep Foundation.
Sleep Disturbances ‘ Highly Prevalent ‘ Among UK Adults
The UK Biobank enrolled just over 500,000 people aged 37-73 years during 2006-2010, and 487,728 of these people had data available that allowed their inclusion in the analysis. That group averaged about 57 years of age, 54% were women, 94% were White, and their average body mass index was 27-28 kg/m2.
More than a quarter of these people reported having “usual” sleep disturbances, showing that sleep disturbances are “highly prevalent” among U.K. residents, noted the authors. Just under a quarter of the subjects reported they never or rarely had sleep disturbances, and the remaining half of subjects said they “sometimes” had sleep disturbances.
In addition, 69% reported neither diabetes nor frequent sleep disturbances, 26% had frequent sleep disturbances but no diabetes, 3% had diabetes but not frequent sleep disturbances, and 2% had both diabetes and frequent sleep disturbances.
During the average 8.9-year follow-up, 19,177 people died from any cause (4%), and 3,874 of these deaths involved cardiovascular disease causes. Despite the significant association of diabetes and frequent sleep disturbances with an increased rate of all-cause mortality, the same combination showed no significant link with cardiovascular mortality in the study’s full-adjusted model. This may be because “frequent sleep disturbances can lead to a variety of causes of death,” Knutson suggested.
The information collected by the UK Biobank did not allow the researchers to distinguish between type 1 and type 2 diabetes.
The findings “suggest that regardless of the cause of sleep disturbance, reporting sleep disturbances on a frequent basis is an important signal of elevated risk of mortality. Such symptoms should therefore be investigated further by physicians, particularly in patients who have also been diagnosed with diabetes,” wrote Knutson and coauthors. “This is the first study to examine the effect of the combination of insomnia and diabetes on mortality risk.”
But Knutson highlighted that “sleep problems are important for everyone, not just people with diabetes.
Neither Knutson and coauthors nor Reutrakul had no disclosures.
This article originally appeared on MDedge.com, part of the Medscape Professional Network.