Neuropsychological changes and treatment compliance in older adults with sleep apnea

Apnea is a common disorder in older adults and has been shown to affect cognition. Some studies suggest that treatment for apnea improves certain cognitive deficits, but few studies have examined the relationship between compliance and cognitive improvement. We designed a study to answer the following questions about sleep apnea, cognition and treatment in older adults: (1) Which neuropsychological (NP) variables are differentially associated with measures of sleep fragmentation and oxygen desaturation? (2) Does compliant use of CPAP provide a cognitive advantage over noncompliant use? (3) Does NP performance at baseline predict compliance at 3 months?

Twelve participants were recruited for the study. All had polysomnographically defined sleep apnea with an RDI of 10 or greater. All were also at least 55 years of age, had no other diagnosable sleep disorder and had no previous treatment for sleep apnea syndrome (SAS). Participants were administered a full NP battery before and 3 months after treatment with CPAP. RDI at baseline was associated with delayed verbal recall, while oxygen desaturation was associated with both delayed recall and constructional abilities. Compliant use of CPAP at 3 months was associated with greater improvements in attention, psychomotor speed, executive functioning and nonverbal delayed recall. Finally, attention measures predicted compliance at 3 months suggesting that those who were least vigilant at baseline were more likely to comply with treatment.

Results are discussed in terms of the relevance to targeting special populations for compliance interventions, the ways that treatment may specifically affect older adults and the possible dose-response relationship of CPAP.