Study Underlines Importance of Quality Sleep in Patients with Diabetes

Underlining the importance of quality sleep to overall health, new research from Northwestern University suggests patients with diabetes who experienced frequent sleep disturbances were 87% more likely to die than those with neither in the next 9 years.

An analysis of data from the UK Biobank cohort, results suggest frequent sleep disturbances and diabetes alone were associated with a 12% and 67% increase in risk of all-cause mortality, respectively, but the combination of both resulted in an 87% increase in risk of mortality over 8.9 years of follow-up.

"Diabetes alone was associated with a 67% increased risk of mortality. However, the mortality for participants with diabetes combined with frequent sleep problems was increased to 87%. In other words, it is particularly important for doctors treating people with diabetes to also investigate sleep disorders and consider treatments where appropriate,” said senior investigator Kristen Knutson, PhD, Associate Professor of Neurology and Preventive Medicine at Northwestern University Feinberg School of Medicine, in a statement.

With an interest in expanding the current knowledge base related to associations between diabetes, sleep disturbances, and mortality, Knutson and a team of colleagues from Northwestern’s Center for Circadian and Sleep Medicine and the University of Surrey designed the present study as an analysis of data from within the UK Biobank cohort. Using patients with full information related to sleep data and clinical characteristics, investigators identified a final cohort of 487,728 participants for inclusion in their analysis.

As part of the UK Biobank protocol, patients were asked about the frequency they experience sleep disturbances and responses were classified as never/rarely, sometimes, or usually. The primary outcomes of interest for analyses were mortality all causes and cardiovascular mortality.

For the purpose of analysis, investigators planned to conduct multiple analyses assessing sleep disturbances with risk of mortality. The first was adjusted for age and sex only while the second was fully adjusted for clinical factors and 11 different comorbidity variables.

Baseline analyses indicated 24.2% (n=118,217) reported never/rarely experiencing sleep disturbances while 47.8% (n=233,177) reported sometimes experiencing sleep disturbances and 28% (n=136,334) usually experiencing sleep disturbances. Overall, 69% of the study sample had no diabetes and report never/rarely experiencing sleep disturbances, 26% had frequent sleep disturbances but no diabetes, 3% had diabetes but no frequent sleep disturbances, and 2% had diabetes and frequent sleep disturbances.

Compared to those never/rarely experiencing sleep disturbances, patients with frequent sleep disturbances were older, had a higher BMI, slept less, and were more female, white, current smokers, and have depression or diabetes.

During the follow-up period, which lasted a mean of 8.9 years, 19,177 all-cause deaths and 3874 cardiovascular-specific deaths occurred among the study cohort. In the fully adjusted model, results indicated those with frequent sleep disturbances alone were at an 11% (HR, 1.11; 95% CI, 1.07-1.15) increased risk, those with diabetes alone were at a 67% (HR, 1.67; 95% CI, 1.57-1.76) increased risk, and those with both were at an 87% (HR, 1.87; 95% CI, 1.75-2.01) increased risk of all-cause mortality. Investigators also noted results suggested presence of sleep disturbances and diabetes was associated with a 12% (HR, 1.12; 95% CI, 1.04-1.22) increase in risk of mortality compared to patients with diabetes and no frequent sleep disturbances.

When assessing cardiovascular mortality, results indicated diabetes alone was associated with a 2-fold increase in risk (HR, 2.04; 95% CI, 1.84-2.27) while diabetes and frequent sleep disturbances were associated with further increased risk (HR, 2.11; 95% CI, 1.85-2.40). However, investigators pointed out no significant difference for cardiovascular mortality was observed for those with diabetes and frequent sleep disturbances versus those with diabetes and no frequent sleep disturbances (HR, 1.03; 95% CI, 0.89-1.20).

"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,” added lead investigator Malcom von Schantz, PhD, Professor of Chronobiology from the University of Surrey, in the aforementioned statement.

This study, “Associations between sleep disturbances, diabetes and mortality in the UK Biobank cohort: A prospective population-based study,” was published in Journal of Sleep Research.