Summary: Severe obstructive sleep apnea is linked to an increase of the amyloid beta protein, resulting in a greater risk of sufferers developing dementia.

Source: Monash University

A new study by Monash University has found that obstructive sleep apnea (OSA) has been linked to an increased risk of dementia.

The study, published in the Journal of Alzheimer’s Disease, and led by Dr Melinda Jackson from the Turner Institute for Brain and Mental Health, found that severe OSA is linked to an increase in a protein, called beta-amyloid, that builds up on the walls of the arteries in the brain and increases the risk of dementia.

The study involved 34 individuals with recently diagnosed untreated OSA and 12 individuals who were asymptomatic for sleep disorders. It explored associations between brain amyloid burden using a PET brain scan, and measures of sleep, demographics and mood.

The OSA group recorded a higher amyloid burden, poorer sleep efficiency and less time spent in stage N3 sleep (a regenerative period where your body heals and repairs itself).

OSA is a common sleep disorder, affecting about 1 billion people worldwide and is caused by the collapse of the airway during sleep, resulting in intermittent dips in oxygen levels and arousals from sleep.

“The significance of finding the association between increased brain amyloid in patients with OSA will allow for further research to explore in more detail the implications of treating OSA for reducing dementia risk,” Dr Jackson said.

About this dementia research news

Source: Monash University
Contact: Wendy Smith – Monash University
Image: The image is in the public domain

Original Research: Closed access.
“Severe Obstructive Sleep Apnea is associated with higher amyloid burden. A preliminary PET imaging study” by Melinda Jackson et al. Journal of Alzheimer’s Disease

Severe Obstructive Sleep Apnea is associated with higher amyloid burden. A preliminary PET imaging study

Obstructive sleep apnea (OSA) has been linked to an increase risk of dementia. Few studies have cross-sectionally examined whether clinically-confirmed OSA is associated with a higher brain amyloid burden.

Objective:

The aim of this study was to compare brain amyloid burden in individuals with untreated OSA and healthy controls, and explore associations between amyloid burden and polysomnographic and subjective measures of sleep, demographics, and mood.

Methods:

Thirty-four individuals with OSA (mean age 57.5±4.1 y; 19 males) and 12 controls (mean age 58.5±4.2 y; 6 males) underwent a clinical polysomnogram and a 11C-PiB positron emission tomography (PET) scan to quantify amyloid burden. Results:Amyloid burden was elevated in the OSA group relative to controls, and was significantly higher in those with severe OSA relative to mild/moderate OSA. Correlation analyses indicated that higher amyloid burden was associated with a higher Non-REM apnea hypopnea index, poorer sleep efficiency, and less time spent in stage N3 sleep, when controlling for age.

Conclusion:

Severe OSA is associated with a modest elevation of brain amyloid, the significance of which should be further investigated to explore the implications for dementia risk.