Protective Effect of Long-Term CPAP Therapy on Cognitive Performance in Elderly Patients with Severe OSA: The PROOF Study.

Objective: Obstructive sleep apnea syndrome (OSA) leads to a deterioration in cognitive functions, with regard to memory and executive functions. However, few studies have investigated the impact of treatment on these cognitive functions in elderly subjects.

Methods: The study was conducted in a large cohort of subjects aged 65 years or older (the PROOF cohort). Subjects were not diagnosed or treated for OSA. Subjects underwent a polygraphic recording. Cognitive performance was assessed in all OSA subjects at baseline and 10 years later, whether or not they were receiving continuous positive airway pressure (CPAP) therapy.

Results: A group of 126 patients were analyzed. Only 26% of them were treated, with therapy initiated at the discretion of the primary care physician. Among treated subjects, self-reported compliance with therapy was good (> 6 h/night on average), and 66% of them reported an improvement in their quality of life. Patients receiving CPAP treatment had a higher apneahypopnea index (p = 0.006), a higher oxygen desaturation index (p < 0.001), and experienced more pronounced daytime repercussions (p = 0.004). These patients showed a statistically significant improvement in mental agility (similarities test; p < 0.0001) and memory performance (Grober and Buschke delayed free recall; p = 0.02).

Conclusion: CPAP treatment is associated with the maintenance of memory performance over time.