Sleep characteristics in type 1 diabetes and associations with glycemic control: systematic review and meta-analysis.

OBJECTIVES: The association between inadequate sleep and type 2 diabetes has garnered much attention, but little is known about sleep and type 1 diabetes (T1D). Our objectives were to conduct a systematic review and meta-analysis comparing sleep in persons with and without T1D, and to explore relationships between sleep and glycemic control in T1D. METHODS: Studies were identified from Medline and Scopus. Studies reporting measures of sleep in T1D patients and controls, and/or associations between sleep and glycemic control, were selected. RESULTS: A total of 22 studies were eligible for the meta-analysis. Children with T1D had shorter sleep duration (mean difference [MD] = -26.4 minutes; 95% confidence interval [CI] = -35.4, -17.7) than controls. Adults with T1D reported poorer sleep quality (MD in standardized sleep quality score = 0.51; 95% CI = 0.33, 0.70), with higher scores reflecting worse sleep quality) than controls, but there was no difference in self-reported sleep duration. Adults with TID who reported sleeping >6 hours had lower hemoglobin A1c (HbA1c) levels than those sleeping ≤6 hours (MD = -0.24%; 95% CI = -0.47, -0.02), and participants reporting good sleep quality had lower HbA1c than those with poor sleep quality (MD = -0.19%; 95% CI = -0.30, -0.08). The estimated prevalence of obstructive sleep apnea (OSA) in adults with TID was 51.9% (95% CI = 31.2, 72.6). Patients with moderate-to-severe OSA had a trend toward higher HbA1c (MD = 0.39%, 95% CI = -0.08, 0.87). CONCLUSION: T1D was associated with poorer sleep and high prevalence of OSA. Poor sleep quality, shorter sleep duration, and OSA were associated with suboptimal glycemic control in T1D patients.

Higher sleep variability is associated with poorer glycaemic control in patients with type 1 diabetes.

Sleep disturbances have been linked to insulin resistance and poor glycaemic control in patients with type 2 diabetes. However, the data are limited in type 1 diabetes. Recently, varying day-to-day sleep schedules, i.e. sleep variability, have been associated with adverse metabolic profile in healthy individuals. This study explored whether sleep variability affects glycaemic control and insulin requirement in type 1 diabetes. Forty-one adult patients with type 1 diabetes wore an actigraphy for 5 nights. Standard deviation of sleep duration, efficiency and mid-sleep time were sleep variability parameters. Sleep apnoea risk and self-reported sleep quality were assessed by the Berlin questionnaire and Pittsburgh Sleep Quality Index. Haemoglobin A1c, diabetes complications and insulin regimen were obtained from medical records. After adjusting for neuropathic symptoms, sleep apnoea risk and poor self-reported sleep quality, higher sleep variability was significantly associated with poorer glycaemic control (standard deviation of sleep duration, B = 0.100, P = 0.004; and standard deviation of mid-sleep time, B = 0.068, P = 0.04). In addition, standard deviations of sleep duration and mid-sleep time were highly correlated, suggesting that participants changed their sleep duration along with sleep timing. After adjusting for covariates, the standard deviation of sleep duration (P = 0.009) and standard deviation of mid-sleep time (P = 0.012) were associated with higher insulin requirement. In summary, higher sleep variability, which likely reflects sleep deprivation alternating with sleep compensation along with shifts in their circadian timing, was associated with poorer glycaemic control and higher insulin requirement in patients with type 1 diabetes. Increased sleep regularity may improve metabolic control in type 1 diabetes.