From the Guidelines
Yes, untreated Obstructive Sleep Apnea (OSA) can cause cognitive decline, as it disrupts normal sleep patterns, leading to decreased oxygen levels in the blood and fragmented sleep, which can impair various cognitive functions. Sleep apnea is a breathing disorder characterized by narrowing of the upper airway that impairs normal ventilation during sleep, and its consequences are wide ranging, including impairments in vigilance, concentration, cognitive function, social interactions, and quality of life (QOL) 1. The brain is particularly vulnerable to oxygen deprivation, and the repeated episodes of low oxygen (hypoxia) that occur with sleep apnea can damage brain tissue over time.
According to the American Academy of Sleep Medicine, individuals with OSA often feel unrested, fatigued, and sleepy during the daytime, and may suffer from impairments in cognitive function, which can translate into higher rates of job-related and motor vehicle accidents 1. Furthermore, research suggests that treating sleep apnea with continuous positive airway pressure (CPAP) therapy may improve cognition and decrease the risk of dementia, as recommended by the 5th Canadian Consensus Conference on the Diagnosis and Treatment of Dementia 1.
Key points to consider include:
- Untreated OSA can lead to cognitive decline, including impairments in attention, memory, executive function, and information processing speed
- Sleep apnea disrupts normal sleep patterns, leading to decreased oxygen levels in the blood and fragmented sleep
- Treatment options for OSA include CPAP therapy, oral appliances, positional therapy, weight loss, and surgery
- Early diagnosis and treatment are crucial to prevent or minimize long-term cognitive consequences, as emphasized by the American Academy of Sleep Medicine 1 and the 5th Canadian Consensus Conference on the Diagnosis and Treatment of Dementia 1.
Therefore, it is essential to prioritize the diagnosis and treatment of OSA to prevent or minimize cognitive decline and other related consequences.
From the Research
Cognitive Decline in Untreated Obstructive Sleep Apnea (OSA)
- Untreated OSA has been associated with cognitive decline, particularly in attention, vigilance, and information processing speed 2.
- The presence of OSA seems to have a significant impact on the development and progression of mild cognitive impairment (MCI) 2.
- Cognitive deficits in OSA patients can resemble dementia, making it essential to consider OSA in the diagnosis of cognitive decline 3.
- Executive function, attention, verbal/visual long-term memory, visuospatial/constructional ability, and information processing are more likely to be affected in OSA patients, whereas language, psychomotor function, and short-term memory are less likely to be affected 4.
Mechanisms Underlying Cognitive Decline in OSA
- Increased accumulation of Aß2-amyloid in the brain, episodic hypoxemia, oxidative stress, vascular inflammation, and systemic comorbidities may contribute to the pathogenesis of cognitive decline in OSA 4.
- Sleep disruption and blood gas abnormalities are thought to be the primary determinants of cognitive deficits in OSA 5.
- Hypoxia/hypercarbia may be an important determinant of deficits in attention, memory, executive function, psychomotor function, and language abilities in OSA 5.
Treatment and Cognitive Outcomes
- Treatment with continuous positive airway pressure (CPAP) may improve cognitive symptoms in OSA patients 2, 4, 6.
- CPAP treatment can mitigate and slow the rate of cognitive decline and may reduce the risk of dementia 2.
- High-intelligence may have a protective effect against OSA-related cognitive decline, perhaps due to increased cognitive reserve 6.