Amyloid plaques have been identified in the brains of people with obstructive sleep apnea, similar to those seen in Alzheimer’s disease.
- People suffering from obstructive sleep apnea are potentially susceptible to developing Alzheimer’s disease, especially if sleep apnea appears around the age of 40.
- According to the Australian researchers, this is linked to the amyloid plaques found in both diseases, which accumulate in the brain near neurons.
- These results confirm those found by Inserm researchers in March 2020, who also saw a link between the two diseases.
Amyloid plaques form as a result of the accumulation of beta-amyloid protein. They are found near neurons and partially block their functioning. For several years, science has identified their involvement in Alzheimer’s disease. A research from the Royal Institute of Technology in Melbourne (Australia) shows that these same plaques have been identified in the brains of people with obstructive sleep apnea. Their formation begins in the same places and their development is similar.
Known but unexplained links
“We know that if you have sleep apnea in your 40s, you are more likely to develop Alzheimer’s disease as you age, and if you have Alzheimer’s, you are more likely to suffer from sleep apnea than other people your age”, says Stephen Robinson, the main author of this research. In March 2020, Inserm researchers also found links between the two pathologies: people suffering from sleep apnea had an accumulation of beta-amyloid proteins in the brain. “This does not mean that these people will necessarily develop the disease, but they are at higher risk”, had declared the director of the study, Géraldine Rauchs. However, the nature of the link between the two diseases remains mysterious.
Plates still present despite treatment
To better understand it, the researcher and his team performed autopsies of the hippocampus of 34 people and the brainstem of 24 people with obstructive sleep apnea. The researchers found that the more severe the obstructive sleep apnea, the greater the buildup of amyloid plaques. “In the case of obstructive apnea of moderate severity, you find amyloid plaques and neurofibrillary degeneration only in the cerebral cortex near the hippocampus, exactly where they are present at the onset of Alzheimer’s disease”, underlines the scientist. To treat obstructive sleep apnea, one of the techniques consists of blowing air into the nasal passages, continuously, during the night. In treated people, this method did not change the amount of amyloid plaques present in the brain. None of the people whose brains were analyzed had been diagnosed with dementia or Alzheimer’s disease during their lifetime. The research team wishes to continue working on these samples to identify possible signs of inflammation or transformation of the blood vessels. They also want to launch a clinical study with a larger cohort.
A widespread disease in the world
Obstructive sleep apnea affects more than 930 million people worldwide. In France, 4% of the population would be affected. It results in pauses of 10 to 30 seconds in breathing during the night. Sufferers often suffer from daytime drowsiness, difficulty concentrating and have a higher risk of road accidents, given the lack of alertness associated with fatigue. Thanks to treatment, or even surgery in some cases, these side effects of sleep apnea can decrease or even disappear.
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