Comorbid insomnia and sleep apnea is associated with worse verbal episodic memory in older females.

STUDY

OBJECTIVES

To investigate whether comorbid insomnia and sleep apnea (COMISA) is associated with poor verbal memory in older adults, and whether this relationship is moderated by sex.

METHODS

A total of 110 older adults aged (65-83), all diagnosed with obstructive sleep apnea, completed overnight polysomnography and cognitive testing. COMISA was defined as obstructive sleep apnea plus an Insomnia Severity Index score ≥ 11. Verbal memory was assessed via the delayed recall component of the Alzheimer's Disease Cooperative Study Preclinical Alzheimer's Cognitive Composite. Moderation analysis examined the interaction between COMISA and sex on verbal memory performance, adjusting for age, body mass index, APOE4 status, and education. Post hoc sleep architecture differences between males and females with COMISA and females with COMISA compared to obstructive sleep apnea only were analyzed using multivariate analysis of covariance.

RESULTS

COMISA was associated with significantly worse verbal memory performance, with this effect driven by females (b = -2.82, standard error = 0.94, t = -3.01, P = .003) and absent in males (b = 0.62, standard error = 0.97, t = 0.63, P = .528). Post hoc analyses revealed that females with COMISA showed reduced rapid eye movement sleep and increased slow wave sleep compared to males with COMISA.

CONCLUSIONS

COMISA is linked to sex-specific cognitive vulnerability, with older females showing worse verbal memory than males. Post hoc analyses revealed differences in sleep architecture by sex within COMISA, warranting further investigation into stage-specific sleep contributions to cognitive risk. These findings highlight the importance of sex-informed approaches to assessing and managing cognitive risk in aging populations.

CLINICAL TRIAL REGISTRATION: Registry: ClinicalTrials.gov; Name: Is Obstructive Sleep Apnea Important in the Development of Alzheimer's Disease?; URL: https://clinicaltrials.gov/study/NCT05094271; Identifier: NCT05094271.

CITATION: Holloway BM, Harding CD, DeYoung P, et al. Comorbid insomnia and sleep apnea is associated with worse verbal episodic memory in older females. J Clin Sleep Med. 2025;21(12):2129-2138.