Sleep Disordered Breathing Linked to Alzheimer Risk

Data from several new analyses reported at the Alzheimer’s Association International Conference 2017 in London indicate potential, significant associations between sleep disordered breathing (SDB) and biomarkers for Alzheimer disease.

The 3 analyses were reported by researchers at Wheaton College in Wheaton, Illinois.
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In the first analysis, researchers examined brain β-amyloid-42 accumulation in a cohort of 516 cognitively normal adults. They found those participants with SDB had higher levels of β-amyloid-42 in cerebrospinal fluid (CSF) at baseline and a more rapid accumulation over time. However, no interactive effects were observed between obstructive sleep apnea and the Alzheimer risk gene APOE-e4.

In the second analysis, researchers examined data from 798 participants with mild cognitive impairment (MCI), finding that both baseline and rate of accumulation of β-amyloid-42 were higher in individuals with obstructive sleep apnea, suggesting that SDB may be an independent risk factor for Alzheimer disease.

In a combined analysis of both the cognitively normal and the mild cognitive impairment populations, along with a third group of participants with Alzheimer disease (n=325), researchers evaluated the effects of SDB on levels of several Alzheimer disease biomarkers in CSF and used positron emission tomography to measure β-amyloid-42.

Overall, they found:

• Associations between SDB and CSF β-amyloid-42 levels in the mild cognitive impairment and Alzheimer groups.
• Significant obstructive sleep apnea associations with brain β-amyloid-42 levels in cognitively normal and mild cognitive impairment participants.
• Obstructive sleep apnea patients experienced faster increase in brain β-amyloid-42 over time in the cognitively normal and mild cognitive impairment groups.
• Obstructive sleep apnea participants experienced a faster decrease in CSF β-amyloid-42 and increases in TAU and PTAU volumes over time in both the CN and MCI groups.

These results "highlight the importance of checking for and accurately diagnosing sleep disordered breathing, especially in people at risk for dementia, and more importantly in people diagnosed with MCI, so that it can be addressed and treated,” according to the researchers.

—Michael Potts

Reference:

Can treating sleep problems lower dementia risk? [press release]. July 18, 2017. London, UK. https://www.alz.org/aaic/releases_2017/AAIC17-Tues-Briefing-Sleep.asp.