Links between untreated Obstructive Sleep Apnea (OSA) and dementia.

There are a number of well-known risks from the side effects of untreated obstructive sleep apnea (OSA), such as the increased risk of hypertension, greater risk of developing type 2 diabetes, as well as other risks. However, recent research has begun to uncover a connection between untreated sleep apnea and increased dementia.

Older man with his head in his hands

Do studies link OSA to an increase in dementia risks?

It’s not easy to stay on top of the latest research when it comes to sleep apnea as there’s so much. This is difficult due to the volumes now being published as the strength of evidence increases. The studies which link sleep apnea to increased risks of developing dementia are still limited in scope and based on the number of trial participants and repeated teats, yet there does appear to be some links which we should all be aware of.

What is Dementia? 

Dementia is a syndrome in which there is deterioration in memory, thinking, behaviour and the ability to perform everyday activities. It is not a normal part of ageing.

Is Dementia common?

Worldwide, around 50 million people have dementia, more than 400,000 in Canada and there are nearly 10 million new cases every year, over 75,000 within Canada.

There appears to be a connection between sleep disruptions and cognitive impairment in senior women. As many studies on sleep apnea focus on men, this study is also unique for having exclusively female participants. 

Is there a link between OSA and an increase in dementia risk?.

Tau, is a protein marker found in Alzheimer’s sufferers brains and in 2019 this protein marker that is linked to Alzheimer’s disease in the brains of those who had sleep disruptions. The study participants who had untreated obstructive sleep apnea had higher amounts of tau markers — which is the protein marker that creates tangles in the brain. 


Early testing and intervention can decrease sleep apnea complications.

When it comes to sleep apnea, early intervention is the key to enjoying the best possible results. Testing for potential OSA is not difficult.


With suspected OSA, it is “better to be safe than sorry” – so instead of wondering if your sleep issues are due to obstructive sleep apnea, ask your doctor to arrange testing as soon as possible.

I’ve treated a doctor with dementia, and watched my mother’s health fail catastrophically with Alzheimer’s disease before her death. Both had OSA. Anything we can do to avoid this cruel disease is worthwhile – especially if it improves the quality of life anyway.

Dr Stephen Bray