Changes in cognitive function associated with sleep disordered breathing in older people.

Area of Science:

• Gerontology
• Sleep Medicine
• Cognitive Neuroscience

Background:

• Sleep disordered breathing (SDB) is prevalent in older adults, often linked to functional impairments like excessive daytime sleepiness and cognitive deficits.
• Previous research suggests a connection between SDB and cognitive decline, but the specific mechanisms require further elucidation.

Purpose of the Study:

• To investigate the relationship between sleep disordered breathing (SDB) and cognitive function in an aging population.
• To determine if daytime sleepiness or SDB severity is the primary driver of cognitive impairment in older adults.

Main Methods:

• A population-based longitudinal study involving community-dwelling older adults (age 65+) at high risk for SDB.
• In-home interviews, sleep recordings, and cognitive assessments (Mini-Mental State Examination) were conducted over multiple visits.
• Data from 46 participants who completed Visit 3 and Visit 4 were analyzed.

Main Results:

• Increases in respiratory disturbance index (RDI) and daytime sleepiness were associated with decreased cognitive performance.
• However, in a comprehensive model, only increased daytime sleepiness remained significantly associated with cognitive decline (decreased MMSE scores).
• No significant relationship was found between changes in oxygen saturation and cognitive function.

Conclusions:

• Declining cognitive function in older adults is primarily associated with increased daytime sleepiness.
• The relationship between SDB and cognitive function may be mediated by daytime sleepiness.
• Treatment of SDB could benefit older patients with mild to moderate SDB by improving cognitive function, even in the absence of significant hypoxemia.