The impact of sleep duration and sleep quality on glycaemic control in Asian population with type 2 diabetes mellitus: A systematic literature review and meta-analysis of observational studies

Aim: Excessive and insufficient sleep disrupts glycaemic control in patients with type 2 diabetes mellitus (T2DM). However, the evidence underlying the association between sleep duration, sleep quality and glycaemic control in Asian diabetic population remains unclear. We aimed to perform a systematic literature review and meta-analysis of observational studies to examine the sleep duration and sleep quality on glycaemic control in Asian population with T2DM. Methods: A systematic search was performed on PubMed and Embase from inception through April 2019 to identify studies assessing the relationship between sleep duration, sleep quality and glycemic control in Asian population with T2DM. Estimated the pooled mean difference (MD) and 95% confidence intervals (CIs) using a weighted random-effect model. Results: Overall, seven studies were included in the meta-analysis. The results suggesting short sleep was associated with significantly higher HbA1c levels compared to normal sleep (MD: 0.11; 95% CI: 0.06-0.17). While long sleep duration was associated with significantly higher fasting plasma glucose levels (FPG) (MD: 5.30; 95% CI: 3.27-7.34) compared to normal sleep duration. Good sleep quality was significantly reduced the FPG levels (MD: 11.28; 95% CI: 5.13-17.42), compared to poor sleep quality. Conclusions: Our study suggested that sleep duration, as well as the quality of sleep, is thought to be an important factor in the metabolic function of type 2 diabetes patients. Further studies warrant to confirm the present findings and to establish the potential causal relationship between sleep and glycaemic control.