Researchers may have discovered another piece of the Alzheimer's puzzle. Studies revealed at the Alzheimer's Association International Conference held in London show additional evidence that patients with sleep apnea have an increased chance of developing dementia. Some forms of dementia can progress to Alzheimer's Disease.
Alzheimer’s disease is one of the most prevalent forms of dementia. A person can have Alzheimer's for years before developing recognizable symptoms. While the causes of Alzheimer’s and dementia are not entirely clear, they are thought to be caused by a combination of environmental and genetic factors.
Researchers may have discovered another piece of the Alzheimer's puzzle. Studies revealed at the Alzheimer's Association International Conference held in London show additional evidence that patients with sleep apnea have an increased chance of developing dementia. Some forms of dementia can progress to Alzheimer's Disease.
Alzheimer’s disease is one of the most prevalent forms of dementia. A person can have Alzheimer's for years before developing recognizable symptoms. While the causes of Alzheimer’s and dementia are not entirely clear, they are thought to be caused by a combination of environmental and genetic factors.
The Sleep Apnea Connection
Beta-Amyloids that build in the brain are a key marker for diagnosing Alzheimer’s disease. Sleep apnea and disordered breathing cause amyloids to build in the brain. Neural imaging has clarified the connection between sleep apnea and dementia.
This connection between sleep disorders and dementia had been made previously, but it was originally determined that people who were at risk of Alzheimer's were also at risk for sleep-disordered breathing. Early research did not show the whole picture.
Sleep Disordered Breathing Creates Beta-Amyloids
With the use of a PET scan, it was determined that breathing disturbances during sleep caused the beta-amyloid plaque to build up in the brain before the subject showed any indication of mental decline. Researchers tested subjects with and without symptoms of cognitive decline and saw the same results with both sets of test subjects. Sleep apnea accelerated cognitive decline in patients who showed no impairment just a few years prior.
Oxygen Deprivation Accelerates the Process
It is now believed that either oxygen deprivation accelerates the production of beta-amyloid or that the lack of REM sleep caused by the apnea disrupts the brains glymphatic system. The glymphatic system, the process of waste removal, may require REM sleep to clear away the proteins that turn into plaque. It is the plaque in the brain that causes the cognitive decline. Treating sleep apnea and improving REM sleep allows for improved protein removal, reducing beta-amyloid plaque formation.
Apnea Treatment May Slow the Cognitive Decline of Alzheimer’s
Experts in Alzheimer’s research believe that treating sleep apnea can slow the progression of Alzheimer's disease. CPAP, dental appliances and positional therapy for sleep apnea may be beneficial for those in the early stages of dementia and Alzheimer's disease. Treatment may slow the progression.
Sleep apnea is already known to cause sleepiness, metabolic and cardiovascular dysfunction. The risks of sleep apnea causing cognitive decline and dementia increase as a person ages. This indicates to Alzheimer researchers that developing better screening tools would benefit the elderly who may have sleep apnea but are still free of cognitive symptoms. Proper treatment of breathing disorders could slow the progression of cognitive decline.
Sources:
https://www.alz.org/braintour/plaques.asp
https://www.medicalnewstoday.com/articles/320024.php
https://www.ncbi.nlm.nih.gov/pubmed/25947369
https://www.aarp.org/health/brain-health/info-2017/sleep-apnea-dementia-risk-fd.html
https://www.alz.org/alzheimers_disease_causes_risk_factors.asp#familyhistory