Does Lack of Oxygen During Sleep Accelerate Alzheimer’s Disease?

Breathing disturbances during sleep may play an unsuspected role in the development of Alzheimer’s disease. Obstructive sleep apnea, a common disorder characterized by repeated breathing interruptions at night, exposes the brain to cycles of oxygen deprivation followed by reoxygenation. These fluctuations, known as intermittent hypoxia, are not without consequences for brain cells, particularly astrocytes. Long considered mere supporters of neurons, these cells actually act as oxygen sensors and regulate inflammation, blood flow, and the elimination of toxic waste in the brain.

When a person suffers from sleep apnea, their astrocytes undergo repeated stress. Normally protective, they then become a source of imbalance: they produce more inflammatory molecules and free radicals, substances that damage neurons. Yet, these same mechanisms are involved in Alzheimer’s disease, where there is an abnormal accumulation of toxic proteins such as beta-amyloid and a progressive degeneration of brain cells. By losing their protective function, astrocytes may thus promote the onset and worsening of the lesions typical of the disease.

Epidemiological studies confirm a link between sleep apnea and cognitive decline. People with severe apnea have an increased risk of developing dementia, including Alzheimer’s disease. This risk appears even more pronounced in postmenopausal women, likely due to hormonal and metabolic changes. Conversely, patients with Alzheimer’s disease more often experience nocturnal breathing disorders, suggesting a two-way relationship between these two conditions.

Treating apnea with continuous positive airway pressure, which keeps the airways open during sleep, could offer a way to slow cognitive decline. By improving brain oxygenation, this approach reduces oxidative stress and partially restores brain metabolism. Although the results remain preliminary, they pave the way for better management of modifiable risk factors for dementia.

These findings highlight the importance of screening for and treating sleep apnea, not only to improve sleep quality but also to protect the brain in the long term. They also encourage the exploration of new therapeutic strategies specifically targeting astrocyte dysfunction, in order to break the vicious cycle between oxygen deprivation, inflammation, and neurodegeneration.

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DOI: https://doi.org/10.1007/s11325-026-03651-w

Title: Astrocytes at the crossroads of obstructive sleep apnea and Alzheimer’s disease: from oxygen sensing to neurodegeneration

Journal: Sleep and Breathing

Publisher: Springer Science and Business Media LLC

Authors: J. Cabot; J. B. Soriano; A. Alonso-Fernández; J. J. Rodríguez; J. J. Merino; L. Cànaves-Gómez; N. Gayà-Caro; X. Busquets