Effects of sleep in diabetes: does a good night’s rest and your body’s circadian rhythm impact glycemic control?
Sleep association with type 2 diabetes plays a major role in blood glucose control and how the body responds to insulin, therefore sleep duration and sleep quality is important in adults with type 2 diabetes. Studies have shown an increase in sleep disturbances and poor sleep quality in these adults. In modern society, inappropriate sleep and wake cycles are more prevalent in adults with type 2 diabetes due to work shifts and 24-hour access to engage in activities that disturb the circadian rhythm. With type 2 diabetes being on the rise and obesity as its leading cause, there are nearly 90 million individuals with prediabetes in the U.S. Research has shown that short and long sleep duration and poor sleep quality can lead to higher glucose levels in prediabetes, but further studies have not been done on the association between sleep duration, sleep quality, and inappropriate sleep and wake cycles (e.g., jet lag, shift work) and uncontrolled glucose levels, higher BMI, and increased blood pressure in adults with prediabetes or recently diagnosed untreated type 2 diabetes.
This cohort study assessed the glycemic variables, BMI, and BP in association to sleep variables (sleep duration, sleep efficiency, poor sleep quality) and circadian measures (workday, off days, jet lag, shift work) in patients with prediabetes or recently diagnosed untreated type 2 diabetes. The study evaluated 1,355 obese men and women, ranging from ages 20-65, amongst 4 adult Restoring Insulin Secretion (RISE) centers. Data was collected between the years of 2013 and 2017. After screening for fasting blood glucose, HbA1c, BP, BMI, and OGTT was completed, participants with normal glucose and HbA1c were excluded from the study. There were 704 participants with prediabetes and 258 participants with recently diagnosed untreated type 2 diabetes, who had complete OGTT testing and sleep data. Pittsburgh Sleep Quality Index questionnaire was used to assess the prior month’s self-reported sleep and wake times, and sleep duration on workdays and off days of work. In the study, chronotype was used to describe the participants’ bedtime preference. Women and men in the study were nearly equal in number (437 and 525, respectively); 24.2% of the participants were shift workers.
The results showed that self-reported sleep and sleep and wake cycles between the participants with prediabetes and type 2 diabetes had no significant difference. The P value comparing prediabetes with diabetes in sleep and circadian measures all were <1, which indicates it’s not statistically significant. An average of 32% of all participants duration of sleep in the cohort was less than 6 hours per night. 34.06% of all participants, mostly with prediabetes, reported daytime sleepiness. Participants experiencing poor sleep quality and high apnea risk were highly reported (54.1% and 64.9%).
When measuring the sleep outcomes, participants who reported having <5 and >8 hours of sleep had a mean HbA1c of 5.84%, compared to those with 7-8 hours of sleep having a mean HbA1C of 5.74%. Self-reported sleep duration correlating to OGTT plasma glucose levels and sleep quality, daytime sleepiness, and apnea risk correlating to HbA1c, fasting glucose, or OGTT did not detect any significance. An increased BMI was significantly associated with participants with poorer sleep quality (P=0.028) and that experienced daytime sleepiness (P= 0.045). Daytime sleepiness was also associated with 2.0 mmHg higher systolic BP (P= 0.037).
Circadian outcomes were not significantly associated with HbA1c, fasting glucose, or OGTT. A higher BMI of 1.32 kg/m2 was noted in participants who were shift workers. A social jet lag >2 and chronotype were the only circadian measures associated with a higher systolic BP mean of 131.0 mmHg.
Further studies will need to be conducted to provide clearer answers on whether changes in sleep and circadian measures are needed to show a decrease in the number of patients with prediabetes developing type 2 diabetes.
- Adequate amounts of sleep and circadian measures can have an effect on the body’s glycemic variables, BMI, and blood pressure.
- Long and short sleep durations (<5 hours and >8 hours of sleep) can lead to higher glucose levels.
- Higher BMI is associated with short durations of sleep and shift work in adults with prediabetes or untreated recently diagnosed type 2 diabetes.
Mokhlesi, Babak, et al. “Association of Self-Reported Sleep and Circadian Measures With Glycemia in Adults With Prediabetes or Recently Diagnosed Untreated Type 2 Diabetes.” Diabetes Care, 2019, p. dc190298. Diabetes Care, doi:10.2337/dc19-0298.
“What’s Behind the Link Between Sleep Deprivation and Type 2 Diabetes.” National Sleep Foundation, www.sleepfoundation.org/articles/link-between-lack-sleep-and-type-2-diabetes
Maya Rudolph, Florida A&M University, College of Pharmacy & Pharmaceutical Sciences, PharmD Candidate