Sleep interventions and glucose metabolism: systematic review and meta-analysis

Objective: Sleep disturbances (insufficient or poor sleep quality) have been linked to abnormal glucose metabolism. This systematic review and meta-analysis aimed to explore the effects of behavioral and pharmacological sleep interventions on glucose metabolism. Methods: Medline and Embase were used for systematic search. Studies reporting behavioral or pharmacological interventions in population with sleep disturbances, with measured outcomes of glucose metabolism and sleep parameters were selected. Results: Twenty two studies were eligible for review (eight were conducted in people with type 2 diabetes). Studies were grouped into three types of intervention: sleep extension (n = 6), sleep education or cognitive behavioral therapy for insomnia (CBT-I, n = 6) and pharmacological interventions (n = 10). CBT-I and sleep education resulted in significantly improved self-reported sleep quality (Pittsburgh Sleep Quality Index, mean difference, MD, -1.31, 95% confidence interval (CI) -1.83, -0.80), non-significant reduction in hemoglobin A1c level (MD -0.35%, 95% CI -0.84, 0.13), and non-significant reduction in fasting glucose levels (MD -4.76 mg/dL, 95% CI -14.19, 4.67). Other studies were not eligible for meta-analysis due to heterogeneity of interventions or outcomes. Sleep extension was able to increase sleep duration by varying degrees in short sleepers, and five of six studies demonstrated relationships between the intervention and measures of insulin resistance. A majority of pharmacological intervention studies showed improved sleep but the effects on glucose metabolism were mixed. Conclusions: Available sleep interventions were effective in improving sleep but the effects on glucose metabolism were inconclusive. Larger randomized studies with consistent outcome measurements are needed to demonstrate this potential causal relationship. (C) 2020 Elsevier B.V. All rights reserved.