Researchers working on the EU-funded Silver Santé Study have identified brain changes which explain for the first time why sleep apnea increases the risk of developing Alzheimer’s.

The research, led by Dr Géraldine Rauchs , of Inserm, in Caen, France, was published in JAMA Neurology (https://bit.ly/33HxOIB )

Dr Rauchs and her team studied the effects of sleep apnea on 127 older adults who were taking part in the Age Well clinical trial of the Silver Santé Study. The volunteers, with a mean age of 69, completed neuropsychological assessments (tests to assess how the brain is working), polysomnography (to assess sleep quality and potential sleep disorders) tests and neuroimaging scans.

Those participants with sleep-disordered breathing (SDB or types of sleep apnea) showed greater amyloid burden (protein deposits in the brain), GM volume (number of brain cells) and metabolism (how these cells use glucose for their activity) in brain areas particularly vulnerable to Alzheimer’s – increasing their risk of developing the disease in coming years. No association was found with cognition, self-reported cognitive and sleep difficulties or excessive daytime sleepiness symptoms.

Dr Rauchs, the paper’s author, says: “The results are very significant as although there was increased evidence suggesting sleep-disordered breathing (SBD) increases the risk of developing Alzheimer’s, the brain mechanisms underlying the link were unclear.

“This study shows for the first time that SBD, or sleep apnea, increases amyloid burden, GM volume and metabolism in brain areas particularly vulnerable to Alzheimer’s disease, increasing the risk of these individuals developing the disease in the future. This doesn’t mean, of course, that these participants will necessarily develop Alzheimer’s – just that their risk of developing the disease in future is increased.

“Fortunately, there are effective treatments available for SDB but the results of this study re-emphasize the importance of preserving good sleep quality throughout life in order to safeguard good mental health in later life.”

The results of the Silver Santé Study’s two clinical trials are due to be released later this year.

A volunteer has special headgear fitted by a researcher to monitor their sleep at Inserm in Caen, France.