Do you snore?

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If you snore you should probably make sure you don’t have obstructive sleep apnea (OSA). 

In this study below OSA severity was associated with Alzheimer’s disease pathology burden in the hippocampus the region of the brain responsible for memory. These results indicate that OSA may account for some of the “cognitively normal” individuals who have been found to have substantial amyloid burdens, and are currently considered to be at a prodromal stage of AD.

The implications of this and other studies linking sleep deprivation to Alzheimer’s disease and dementia are profound and imply that sleep hygiene and preventing sleep disorders may be a strategy to reduce the lifetime risk and incidence of dementia. Sleep is critical for the brain to clear itself of protein debris and if you have insufficient sleep the debris accumulates, for example, amyloid plaques associated with Alzheimer's disease. OSA and other sleep disorders may therefore bring forward the AD prodrome and AD by decades. 

OSA is under-diagnosed. It is estimated that about 1 in 10 adults have the condition. The rising incidence of OSA is almost certainly linked to increasing rates of obesity and subtle anatomical changes to our face linked to changes in eating patterns as children, i.e. smaller jaws and more cramped upper airway. There are a large number of sleep applications for your smartphone that you can now download from App stores to monitor your sleep pattern. These apps are not good enough to diagnose OAS, but they will at least give you an idea if you need to be investigated for OSA. This is important as OSA is not only linked to Alzheimer’s disease but a whole host of other problems that can affect your quality of life and day-to-day functioning. Top of the list is excessive daytime sleepiness and the accident risk associated with this problem. Not to mention the associated fatigue and cognitive problems that go with poor sleep quality.

So if your partner or your smartphone complains about your snoring don’t ignore it get yourself screened to exclude OSA. Don’t forget OSA is a treatable condition.

Owen et al. Alzheimer’s disease neuropathology in the hippocampus and brainstem of people with obstructive sleep apnea. Sleep, Volume 44, Issue 3, March 2021, zsaa195, https://doi.org/10.1093/sleep/zsaa195

Obstructive sleep apnea (OSA) involves intermittent cessations of breathing during sleep. People with OSA can experience memory deficits and have reduced hippocampal volume; these features are also characteristic of Alzheimer’s disease (AD), where they are accompanied by neurofibrillary tangles (NFTs) and amyloid beta (Aβ) plaques in the hippocampus and brainstem. We have recently shown reduced hippocampal volume to be related to OSA severity, and although OSA may be a risk factor for AD, the hippocampus and brainstems of clinically verified OSA cases have not yet been examined for NFTs and Aβ plaques. The present study used quantitative immunohistochemistry to investigate postmortem hippocampi of 34 people with OSA (18 females, 16 males; mean age 67 years) and brainstems of 24 people with OSA for the presence of NFTs and Aβ plaques. OSA severity was a significant predictor of Aβ plaque burden in the hippocampus after controlling for age, sex, body mass index (BMI), and continuous positive airway pressure (CPAP) use. OSA severity also predicted NFT burden in the hippocampus, but not after controlling for age. Although 71% of brainstems contained NFTs and 21% contained Aβ plaques, their burdens were not correlated with OSA severity. These results indicate that OSA accounts for some of the “cognitively normal” individuals who have been found to have substantial Aβ burdens, and are currently considered to be at a prodromal stage of AD.

CoI: multiple

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