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.