Obstructive sleep apnea and risk of type 2 diabetes mellitus: A systematic review and dose-response meta-analysis of cohort studies

Background This meta-analysis was performed to quantitatively evaluate the dose-response association between obstructive sleep apnea (OSA) and risk of type 2 diabetes mellitus (T2DM). Methods PubMed, Embase, and Web of Science were searched up to 12 December 2018 for articles that assessed the OSA-T2DM association. Random effects models were used to analyze the quantitative association between OSA and risk of T2DM. Restricted cubic splines were used to model the dose-response association between apnea-hypopnea index (AHI), used to assess the severity of OSA according to events/h, and risk of T2DM. Results We included 16 cohort studies in our meta-analysis. During a median follow-up of 10.5 years (range: 3.0-22.0), 19 355 T2DM cases were reported among 338 912 study participants. The pooled relative risk of T2DM was 1.40 (95% CI, 1.32-1.48) for OSA in the binary meta-analysis and 1.08 (1.01-1.14) for each 5-event/h increase in AHI value. We found a positive linear association between OSA and T2DM risk. Conclusions Our dose-response meta-analysis revealed a linear association between OSA and T2DM. Highlights Obstructive sleep apnea (OSA) is a treatable chronic sleep disorder characterized by episodes of sleep apneas and hypopneas during sleep, increased oxidative stress, inflammation, and sleep fragmentation and is associated with significant comorbidities. Our systematic review and meta-analysis shows that people with OSA are at higher risk of type 2 diabetes mellitus (T2DM), which suggests that we should detect and treat OSA early to prevent T2DM.