Published Online: October 01, 2013
Mary K. Caffrey
For clinicians treating diabetic youth who cannot gain control over glucose levels despite multiple medication changes, it might be time to ask a simple question: Are you getting enough sleep?
Michelle M. Perfect, PhD, assistant professor in the Department of Disability and Psychoeducational Studies at the University of Arizona, presented findings and recommendations at the 73rd Scientific Sessions of the American Diabetes Association (June 21-25, 2013) in Chicago.
Research in this area—especially among teenagers—is scant, despite concerns about the links that connect sleep, glycemic control and daytime functioning in youth with type 1 diabetes mellitus (T1DM). The findings were first reported in the journal SLEEP.1
Yet, according to Perfect, the teenage years are precisely when T1DM patients experience a decline in their adherence to the dietary and management routines needed to keep glucose levels under control. And, like other teenagers, they are likely to be sleep-deprived at a time when rest matters most. One in 400 youth have T1DM, Perfect said, but at present there are no recommendations for how many hours of sleep a diabetic teen should have.
“That’s probably because of the lack of data regarding the role of sleep in these youth,” she said. Perfect said prior to her research, there was only 1 other study that specifically examined the relationship between sleep and glycemic control in youth, and that involved pre-pubescent children.2
Sleep-disordered breathing is typically associated with obesity, but this study looked at the effects of sleep-disordered breathing, independent of the effects of the youth’s body mass index (BMI). Perfect and her co-authors recruited a group of 50 youth aged 10 to 16 years and were able to monitor their sleep through several means: polysomnography, actigraphy, and self-reporting. Sleep-disordered breathing was defined as having an apnea-hypopnea index (AHI) of at least 1.5 events per hour.
Test subjects wore continuous glucose monitors to track A1C levels. Perfect also assessed the test subjects on their daytime sleepiness, depression, and quality of life issues, and asked parents about behavior problems. She also tracked the test subjects’ grades, test scores, and school attendance.
Why might poor sleep affect glucose control? As Perfect explained, sleep-disordered breathing leads to fragmented sleep and elevated cortisol; conversely, a portion of non-REM sleep, the slow wave sleep” or deep sleep, is the restorative period when cortisol levels drop. For youth especially, this is also when a surge in growth hormone occurs. “They need that slow-wave sleep,” she said.
The study’s most significant finding was how even minor levels of sleep-disordered breathing were associated with hyperglycemia. Of the 50 test subjects, 14 had sleep-disordered breathing, and this group ended up having average A1C levels 40 points higher than their counterparts (169.52 mg/dL versus 208 mg/dL). Also, Perfect said, the group with sleep-disordered breathing was hyperglycemic more often, more than half the time at 54.17%, compared with 36.64%.
Poor sleep habits were also associated with reduced scores on the quality-of-life measures and on school performance. Test subjects who spent extended periods in the lighter stage of sleep before slow-wave sleep, and less time in that deep sleep, showed not only higher glucose levels, but also behavioral difficulties, lower grades, depression and poorer attendance. Test subjects with disrupted sleep fared poorly not only when compared with fellow diabetic teens who got better rest, but also when compared with youth in a control group from the Tuscon Children’s Assessment of Sleep Apnea Study.
For those who think attention to sleep is not important, Perfect said, “Look at the data, and tell me sleep is not important.”
With these results, what should clinicians, educators and parents do? Perfect, whose background is in school psychology, recommended treating the sleep issues (she referred some of her test subjects for treatment). For example, she said, snoring could be an indicator that tonsils and adenoids need to be removed.
Perfect is continuing work in this area with a pilot study at how glycemic control improves when diabetic youth can work to extend their sleep. A 10-year-old boy with A1C at 309 mg/dL was able to bring his blood sugar down 45 points by increasing his sleep by 55 minutes, she said. “We need to figure out how to get them to go to bed earlier and get them to school.”
A controlled study of how extending sleep affects health outcomes, funded by the ADA, was getting under way this summer, Perfect said.