Study Finds Connection Between Sleep Apnea and Structural Changes in the Brain

January 22, 2025 TruthUSA

New studies indicate that untreated sleep apnea may result in alterations linked to Alzheimer’s disease.

Sleep apnea not only disrupts your slumber but could also affect brain areas crucial for memory, thereby heightening the risk of developing Alzheimer’s disease.

A comprehensive 10-year study involving nearly 3,000 older Latino adults revealed that individuals with severe sleep apnea exhibit brain changes, including inflammation in memory-related regions.

However, the available research on sleep apnea’s impact on the brain has shown mixed results; some studies have associated sleep disruptions and low oxygenation with brain shrinkage, while others have indicated swelling in brain tissues.

How Sleep Apnea Influences Brain Structure

Growing evidence suggests that sleep apnea alters brain structure.

A recent study published in Neurology on January 14 evaluated participants’ sleep quality through at-home assessments that tracked breathing interruptions and blood oxygen levels.

The researchers analyzed participants’ brain scans taken between 2008 and 2012, followed by additional scans a decade later. They found that those with the most severe cases of sleep apnea and insufficient oxygen during sleep exhibited an enlarged hippocampus and increased white matter lesions—changes correlated with a higher likelihood of cognitive decline and Alzheimer’s disease.

The hippocampus plays a vital role in memory storage and formation. White matter accounts for roughly 50 percent of brain composition, and lesions within it often indicate damaged blood vessels.

The intermittent airflow loss associated with sleep apnea can result in brain damage due to inadequate oxygen supply.

Chronic low oxygen levels combined with disrupted sleep patterns likely lead to inflammation, swelling, and blood vessel damage, imposing stress on the brain and potentially contributing to neuroinflammation that raises Alzheimer’s risk, according to lead author Dr. Alberto R. Ramos from the University of Miami and a fellow of the American Academy of Neurology.

Severe sleep apnea is characterized by having 30 or more breathing interruptions per hour during sleep, while fewer than five interruptions are considered normal.

The Connection Between Sleep, Alzheimer’s, and the Vulnerable Hippocampus

The hippocampus and surrounding brain regions are especially susceptible to low oxygen levels, as they rely heavily on delicate blood vessels that can be harmed when oxygen levels drop during sleep.

This increased vulnerability renders these regions more affected by Alzheimer’s disease, which requires a steady energy supply and is interconnected with other brain areas.

Previous studies have identified hippocampal changes linked to sleep apnea.

A 2018 study published in NeuroImage: Clinical reported both increases and decreases in hippocampal volume associated with obstructive sleep apnea (OSA), the most common form of sleep apnea. The increase in volume was related to inflammation, while the decrease was due to tissue loss and shrinkage. A similar conclusion appeared in a 2022 study that linked severe OSA to an enlarged hippocampus and mild cognitive impairment.

Furthermore, sleep-disordered breathing has been connected to Alzheimer’s-related brain alterations, such as heightened levels of amyloid, a protein responsible for the harmful plaques characteristic of Alzheimer’s disease.

“Although not the central focus of our study, our results correspond with findings that untreated sleep apnea may hasten and induce brain injury that could result in Alzheimer’s-related changes,” Ramos stated.

Sleep, particularly deep slumber, is vital for maintaining brain health and serves as a protective factor against Alzheimer’s disease. In contrast, poor sleep may increase risk. Research indicates that the brain’s waste-clearing system, which removes harmful substances such as beta-amyloid, operates most effectively during sleep.

The Hidden Epidemic of Sleep Apnea

“Timely diagnosis and intervention are crucial to diminish these impacts and safeguard brain health,” Ramos emphasized.

Approximately 80 to 90 percent of individuals with sleep apnea remain undiagnosed. While loud snoring can often be a clue, not all individuals with sleep apnea snore, and not all snorers necessarily have the condition.

The definitive method for diagnosing sleep apnea involves conducting a sleep study, known as polysomnography. Common symptoms prompting evaluation for sleep apnea include excessive daytime sleepiness, abrupt awakenings with gasping, memory problems, mood fluctuations, and frequent nighttime urination.

Managing sleep apnea and adopting healthier sleep routines may help slow or prevent further brain changes, although it’s still unclear if pre-existing damage can be reversed.

The primary treatment for sleep apnea typically involves the use of breathing aids, like a continuous positive airway pressure (CPAP) machine, which maintains airflow to keep airways unobstructed during sleep.

Moreover, doctors might suggest oral appliances such as mouthpieces to ensure airways remain open while sleeping. Surgical options may also be considered to enhance airway functionality.

Lifestyle changes like weight loss, cessation of smoking, and avoiding sedatives or alcohol could also improve sleep quality and potentially mitigate the severity of sleep apnea.

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