The Role of Sleep Duration in Type 2 Diabetes Patients

Lack of adequate sleep may be a risk factor…

Researchers have attempted to determine how many hours of sleep are associated with the lowest risk of type 2 diabetes. The study was a meta-analysis and was performed to assess the relationship between sleep duration and the risk of type 2 diabetes.

The study was designed by conducting a literature search (up to 20 March 2014) of PubMed (Medline) and Embase for prospective studies which examined the association between sleep duration and risk of type 2 diabetes. Studies were included in this meta-analysis if they satisfied the following criteria: the study design was prospective, the exposure of interest was sleep duration, the outcome was type 2 diabetes, and the investigators reported relative risks (RRs) with 95% CIs for at least three quantitative categories of short sleep or long sleep duration.

Research and study selection identified a total of 610 articles from PubMed and 759 articles from Embase prior to 20 March 2014. After exclusion of duplicates and studies that did not fulfill the inclusion criteria, 14 articles remained and 4 more were further excluded to make 10 articles. A total of 18,443 incident cases of type 2 diabetes were confirmed among 482,502 participants with follow-up periods which ranged from 2.5 to 16 years. The meta-analysis reported a U-shaped dose-response relationship observed between sleep duration and risk of type 2 diabetes. The lowest risk was observed at a sleep duration of 7 to 8 hours per day. When compared with a 7 hour sleep duration per day, the pooled relative risks for type 2 diabetes were 1.09 (95% CI 1.04–1.15) for each 1 hour decrease in sleep duration among individuals who slept less than 7 hours per day and 1.14 (1.03–1.26) for each 1 hour increment of sleep duration among individuals with a longer sleep duration.

The researchers concluded that the dose-response of sleep hours recorded by meta-analysis of prospective studies showed a U-shaped relationship between sleep duration and risk of type 2 diabetes. The lowest type 2 diabetes risk was considered to be between 7 to 8 hours per day of sleep duration.

Zhilei Shan. “Sleep Duration and Risk of Type 2 Diabetes: A Meta-analysis of Prospective Studies”. Diabetes Care. March 2015;38:529–537