Effect of continuous positive airway pressure on insulin growth factor-1 in patients with obstructive sleep apnea: A meta-analysis

• A meta-analysis was performed to determine whether effective CPAP therapy could increase IGF-1 levels.
• CPAP therapy is associated with an increase in IGF-1 in patients with OSA.
• Further large-scale, well-designed interventional investigations are needed to clarify this issue.

ObjectiveObstructive sleep apnea (OSA) has been recognized as being associated with low level of insulin growth factor-1 (IGF-1). However, the impact of OSA treatment using continuous positive airway pressure (CPAP) on IGF-1 remains controversial. We performed a meta-analysis to determine whether effective CPAP therapy could increase IGF-1 levels.DesignTwo reviewers independently searched PubMed, Cochrane library, Embase and Web of Science before September 2014. Information on characteristics of subjects, study design and pre- and post-CPAP treatment of serum IGF-1 was extracted for analysis. Standardized mean difference (SMD) was used to analyze the summary estimates for CPAP therapy.ResultsSix articles with 168 patients were included in this meta-analysis, including five observational studies and one randomized controlled study. The meta-analysis showed that CPAP was associated with a statistically significant increase in IGF-1 in OSA patients (SMD = − 0.436, 95% confidence interval = − 0.653 to − 0.218, P = 0.000).ConclusionsThis meta-analysis suggested that CPAP therapy was associated with an increase in IGF-1 in patients with OSA. Further large-scale, well-designed interventional investigations are needed to clarify this issue.