Positive Airway Pressure and Cognitive Disorders in Adults With Obstructive Sleep Apnea: A Systematic Review of the Literature.

BACKGROUND AND OBJECTIVES

Alzheimer disease (AD) and other forms of dementia represent a rising global public health crisis. Because effective treatments to prevent, cure, or slow progression of dementia are unavailable, identification of treatable risk factors that increase dementia risk such as obstructive sleep apnea (OSA) could offer promising means to modify dementia occurrence or severity. Here, we systematically reviewed the impact of positive airway pressure (PAP) therapy on the incidence of cognitive disorders and cognitive decline among middle-aged and older adults with OSA.

METHODS

We performed a systematic search of MEDLINE, EMBASE, Scopus, and CINAHL before May 2021 to identify articles that focused on associations between PAP therapy use and cognitive disorders. We included studies that examined the effects of PAP treatment on (1) the incidence of cognitive disorders among individuals ≥40 years of age diagnosed with OSA and (2) the progression of cognitive decline among people with preexisting cognitive disorders and OSA.

RESULTS

We identified 11 studies (3 clinical trials and 8 observational studies). In these studies, 96% participants had OSA (n = 60,840) and 9% had baseline cognitive impairment (mild cognitive impairment [MCI] or AD) (n=5,826). Of all study participants, 43,970 obtained PAP therapy, and 16,400 were untreated or in a placebo group. Nine out of 11 studies reported a protective effect of PAP therapy on MCI and AD incidence, e.g., delayed age at MCI onset, reduced MCI or AD incidence, slower cognitive decline, or progression to AD.

DISCUSSION

These findings suggest a role for OSA as a modifiable risk factor for cognitive decline. Identification of modifiable risk factors is imperative for alleviating the impact of cognitive disorders on aging adults and their family members. Future research should build on this review and focus on PAP interventions as a potential means to alleviate the incidence of cognitive disorders and cognitive decline, particularly among ethnoracial groups who have been underrepresented and underinvestigated in the extant literature.