Amyloid plaques have been identified in the brains of people with obstructive sleep apnea, similar to those found in those suffering from Alzheimer’s disease.
Amyloid plaques are formed as a result of the accumulation of Amyloid Beta Protein. They are found near neurons and partially block their function. For several years, science has identified their involvement in Alzheimer’s disease. Research at the Royal Melbourne Institute of Technology (RMIT), shows that these same plaques were found in the brain 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 at 40, you have a higher risk of developing Alzheimer’s disease as you get older, and if you have Alzheimer’s, you have a higher risk of developing sleep apnea than other people your age,” says Stephen Robinson, the lead author of this research.
In March 2020 in a study published in JAMA Neurology researchers also found links between the two conditions: people with sleep apnea had an accumulation of amyloid-beta proteins in their brains. “This does not mean that these people will necessarily develop the disease, but they are at greater risk,” said study director Géraldine Rauchs. However, the nature of the link between the two diseases remains unclear.
The plaques are still present, despite treatment
To better understand this, the RMIT research team performed autopsies on the hippocampus of 34 people and the brain stem of 24 people with obstructive sleep apnea. The researchers found that the more severe the obstructive sleep apnea, the greater the accumulation of amyloid plaques. “In moderate obstructive sleep apnea, amyloid plaques and neurofibrillary tangles are only found in the cerebral cortex near the hippocampus, exactly where they are present at the onset of Alzheimer’s disease,” the scientist said. One technique to treat obstructive sleep apnea is to push air into the nasal passages continuously throughout the night. In treated individuals, this method has not altered the amount of amyloid plaques in the brain. None of the people whose brains were examined had been diagnosed with dementia or Alzheimer’s disease during their lifetime. The research team wants to continue working on these samples to identify possible signs of inflammation or changes in blood vessels. They also want to launch a clinical trial with a larger cohort.
A disease that is widespread all over the world
Obstructive sleep apnea affects over 930 million people worldwide. In the US it is estimated that 22 million people suffer from it. Sleep apnea results in stops in breathing during the night that can last on average between 10 to 30 seconds. Affected people often suffer from sleepiness during the day, difficulty in concentration and are at greater risk of road accidents due to lack of alertness caused by fatigue. These sleep apnea side effects can be reduced or even eliminated with treatment, or even surgery in some cases.