A systematic review on adherence to continuous positive airway pressure (CPAP) treatment for obstructive sleep apnoea (OSA) in individuals with mild cognitive impairment and Alzheimer's disease dementia

Obstructive sleep apnoea (OSA) is highly prevalent in mild cognitive impairment (MCI) and Alzheimer’s disease (AD). The gold standard treatment for OSA is continuous positive airway pressure (CPAP). Long-term, well-powered efficacy trials are required to understand whether CPAP could slow cognitive decline in MCI/AD, but its tolerability in this group remains uncertain. The present review investigates CPAP adherence among individuals with OSA and MCI/AD. Electronic searches were performed on 8 databases. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were followed. Six independent studies and four secondary analyses included 278 unique participants (mean age = 72.1 years). In five of the retained studies, around half of participants (45% N = 85 MCI, 56% N = 22 AD) were adherent to CPAP, where 4 hours use per night was considered adherent. Three of the retained studies also reported average CPAP use to range between 3.2 – 6.3 hours/night. CPAP adherence in MCI and AD patients is low, albeit similar to the general elderly population. The question remains as to whether this will be adequate for long-term protection of brain heath.