Executive Dysfunction in OSA Before and After Treatment: A Meta-Analysis

Study Objectives: Obstructive sleep apnea (OSA) is a frequent and often underdiagnosed condition that is associated with upper airway collapse, oxygen desaturation, and sleep fragmentation leading to cognitive dysfunction. There is meta-analytic evidence that sub-domains of attention and memory are affected by OSA. However, a thorough investigation of the impact of OSA on different sub-domains of executive function is yet to be conducted. This report investigates the impact of OSA and its treatment, in adult patients, on 5 theorized sub-domains of executive function. Design: An extensive literature search was conducted of published and unpublished materials, returning 35 studies that matched selection criteria. Meta-analysis was used to synthesize the results from studies examining the impact of OSA on executive functioning compared to controls (21 studies), and before and after treatment (19 studies); 5 studies met inclusion in both categories. Measurements: Research papers were selected which assessed 5 sub-domains of executive function: Shifting, Updating, Inhibition, Generativity, and Fluid Reasoning. Results: All 5 domains of executive function demonstrated medium to very large impairments in OSA independent of age and disease severity. Furthermore, all sub-domains of executive function demonstrated small to medium improvements with CPAP treatment. Discussion: Executive function is impaired across all five domains in OSA; these difficulties improved with CPAP treatment. Age and disease severity did not moderate the effects found; however, further studies are needed to explore the extent of primary and secondary effects, and the impact of age and premorbid intellectual ability (cognitive reserve).