OSA, insomnia linked to poor memory in women

DARIEN, Ill. – New research among older adults with sleep apnea reveals that verbal memory performance is significantly worse in women – but not in men – who also have insomnia. 

According to a new study published in the Journal of Clinical Sleep Medicine, the official publication of the American Academy of Sleep Medicine (AASM), older adults with comorbid insomnia and sleep apnea – often referred to as COMISA – demonstrated worse memory performance than those with sleep apnea alone. This interaction remained significant even after adjusting for age, body mass index, sleep apnea severity, and education. However, when analyzed by sex, COMISA was significantly associated with worse verbal memory outcomes in women, but not in men.  

“We expected that having both insomnia and sleep apnea would worsen memory for everyone, but only older women showed this vulnerability,” said lead author Breanna Holloway, who has a doctorate in clinical psychology and behavioral medicine and is a postdoctoral researcher at UC San Diego School of Medicine. “That was striking, especially because women typically outperform men on verbal memory tasks. The fact that COMISA seemed to offset that advantage hints at a hidden sleep-related pathway to cognitive decline in women. Prior studies have shown increased incidence of Alzheimer's disease in women with untreated sleep apnea.” 

The study involved 110 older adults between the ages of 65 and 83 who were diagnosed with OSA. They completed an overnight sleep study and cognitive testing, and insomnia and verbal memory were assessed using validated tools. COMISA was present in 37% of participants.  

According to the authors, sex differences in sleep architecture may explain the cognitive vulnerability observed in women with COMISA. Post-hoc analyses revealed that women with COMISA had reduced rapid eye movement sleep and more slow wave sleep compared with men, underscoring the importance of considering sex-specific patterns when evaluating COMISA. 

“These results point to an overlooked risk in women with both insomnia and sleep apnea,” said Holloway. “Because women are more likely to have insomnia and often go undiagnosed for sleep apnea, recognizing and treating COMISA early could help protect memory and reduce dementia risk.”