Sleep Breath. 2022 Aug 5. doi: 10.1007/s11325-022-02687-y. Online ahead of print.
PURPOSE: Obstructive sleep apnea (OSA) can impair cognition. Continuous positive airway pressure (CPAP) is a recommended treatment for OSA but its effectiveness on cognitive improvement is uncertain, a finding which may be biased by various durations and adherence to treatment with CPAP. In a meta-analysis assessing high-quality randomized controlled trials (RCTs), we estimated whether or not CPAP benefits cognition in patients with OSA.
METHODS: PRISMA criteria were followed in the performance of this meta-analysis. The weighted mean difference (WMD) and 95% confidence interval (CI) of six neuropsychological scores covering eight cognitive domains were used to evaluate the benefit between CPAP and non-CPAP interventions. Subgroups of different therapeutic durations and adherence, which were divided into short-term (< 8 weeks) and long-term (≥ 12 weeks) durations, and poor (nighttime < 4 h/night) and good (nighttime ≥ 4 h/night) adherence were also analyzed.
RESULTS: Among 16 RCTs, 1529 participants with OSA were included. Comparing the CPAP group and the control group for all treatment durations and adherence, a mild improvement for digit span forward which reflected short-term memory was observed (WMD[95%CI] = 0.67[0.03,1.31], p = 0.04). Trail making test-part B, which reflected executive function was improved for participants with OSA who had good adherence to CPAP (WMD[95%CI] = – 6.24[- 12.60,0.12], p = 0.05). Patients with OSA who received short-term CPAP treatment (WMD[95%CI] = – 7.20[- 12.57, – 1.82], p = 0.009) had a significant improvement in executive function when compared with controls. There was no statistical difference for all scales between long-term (≥ 12 weeks) CPAP treatment group and control group.
CONCLUSION: The effectiveness of CPAP on cognitive improvement in patients with OSA is limited, although good adherence to CPAP can mildly benefit executive function with short-term effectiveness.