Obstructive sleep apnoea-hypopnoea syndrome and cognitive impairments
Sleep apnoea-hypopnoea can occur at any age, but its prevalence increases with age.
Obstructive sleep apnoea-hypopnoea is a common condition involving apnoea (absence of breath) and hypopnoea (reduced airflow).
It causes intermittent hypoxia and poor quality, fragmented sleep. As a result, daytime functioning is significantly impaired with excessive sleepiness, fatigue and mood problems.
Sleep apnoea-hypopnoea is also associated with increased levels of multisystem diseases including hypertension; digestive disease such as nocturnal gastro-oesophageal reflux; urinary disease such as nocturia; cardiovascular events such as arrhythmia; respiratory disease; ischaemic stroke; diabetes mellitus; and a wide range of neurocognitive impairments including problems with memory and even dementia.
A recent study of 298 older women found that 45% of those with sleep apnoea-hypopnoea developed mild cognitive impairment or dementia after an average of five years compared with only 31% of those without the condition.
Sleep apnoea-hypopnoea can occur at any age, but its prevalence increases with age. This may be because of changes in the upper airway including pharyngeal collapsibility, fat deposits around the pharynx and decrease in muscular endurance. There is also a change in the structure of sleep as people age with more frequent shifts from sleep to arousal.
The duration of apnoea-hypopnea may be longer in older people because there is a reduction in the body’s ability to sense and respond to these events. The increase in cognitive impairment may be related to the fact that intermittent hypoxia promotes oxidative stress, which is associated with neuronal cell damage and death. Recent studies have also shown increased plasma markers of systemic inflammation with increased levels of inflammatory cytokines.
Song S, Tan J, Miao Y et al (2017) Obstructive sleep apnea-hypopnea syndrome and cognitive impairments in the elderly. BIO Web of Conferences. 8, 01027. doi: 10.1051/bioconf/20170801027.