Intra‐individual variability in sleep is related to glycaemic control in adults with type 2 diabetes

Abstract

Aims To examine whether there were significant differences in sleep during weekdays/weekends and whether the intra‐individual variability in sleep was related to glycaemic control in patients with type 2 diabetes. Design Correlational, longitudinal design. Methods Data were collected between February 2017–January 2018. In all, 56 adults with type 2 diabetes were included (60.7 years, 55.4% female). Sleep was measured using the Consensus Sleep Diary over 8 days. Intra‐individual variability of sleep was calculated as the standard deviation of sleep variables. Standard deviations of sleep duration, sleep efficiency, sleep quality, and mid‐sleep time were obtained. Glycaemic control was measured by haemoglobin A1C. Paired t test and multiple regression analysis were used. Results Overall, there were no differences in sleep parameters between weekdays and weekends. Participants slept 20 min more over the weekends than during weekdays. The mid‐sleep time during weekends was about 35 min later than during weekdays. Intra‐individual variability of sleep duration and mid‐sleep ranged from 27.6–167.4 min and 13–137 min, respectively. Controlling for covariates (e.g., distress, symptoms, and self‐care), larger variability in sleep duration, and mid‐sleep were significantly related to higher A1C levels. Conclusion Diabetes educators are recommended to include the assessment of intra‐individual variability in sleep. Maintaining a regular sleep habit (e.g., sleep duration and sleep timing) should be highlighted during patient education. Impact Intra‐individual variability in sleep is an alternative dimension for sleep assessment. This study examined whether intra‐individual variability in sleep was related to glycaemic control in an older sample of type 2 diabetes patients using a sleep diary across 8 days. This sample had a similar sleep pattern during weekdays and weekends. Larger intra‐individual variabilities in sleep duration and mid‐sleep time were independently related to worse glycaemic control. Diabetes patients are recommended to maintain a regular sleep routine.

Sleep-Opt-In: A Randomized Controlled Pilot Study to Improve Sleep and Glycemic Variability in Adults With Type 1 Diabetes

“…In a study by Chontong et al 10 , a difference in sleep regularity of ≈20 minutes in adults with T1D was associated with ≈0.6% difference in A1C. Zhu et al 46 also reported that variability in sleep timing was a significant predictor of A1C in adults with type 2 diabetes.…”

Objective sleep characteristics and continuous glucose monitoring profiles of type 2 diabetes patients in real‐life settings

“…The study further suggested that, among different objective sleep variables including sleep duration and sleep efficiency, the variability of sleep duration between nights was most strongly correlated with HbA1c. Another recent study using an 8‐day sleep diary to record sleep variables also reported significant associations between sleep duration variability/sleep midpoint variability and HbA1c among 56 Chinese T2D patients 28 . The mechanism that links variability in sleep duration and midpoint with glycaemic control remains largely obscure.…”

“…Another recent study using an 8‐day sleep diary to record sleep variables also reported significant associations between sleep duration variability/sleep midpoint variability and HbA1c among 56 Chinese T2D patients. 28 The mechanism that links variability in sleep duration and midpoint with glycaemic control remains largely obscure. Noticeably, daily intraindividual variability of sleep has been found to be more pronounced among individuals with insomnia symptoms, poor subjective sleep quality, and late chronotype.…”

Irregular sleep and cardiometabolic risk: Clinical evidence and mechanisms

“…Studies in patients with type 1 diabetes (T1D) suggest that higher sleep duration and midpoint time variability are associated with poorer glycemic control after adjusting for covariates such as neurological symptoms, risk of sleep apnea, and self-reported poor sleep quality (34). In patients with type 2 diabetes (T2D), higher variability in self-reported and actigraphymeasured sleep duration is associated with higher HbA1c values (35,36).…”