Researchers have found a causal relationship between a lack of oxygen to the brain during sleep apnea and Alzheimer’s disease in mice.

Professor Elizabeth Coulson, PhD, from The University of Queensland Queensland Brain Institute and School of Biomedical Sciences and her team found that sleep deprivation alone in mice caused only mild cognitive impairment. But, as Coulson explains in a release, “We developed a novel way to induce sleep-disrupted breathing and found the mice displayed exacerbated pathological features of Alzheimer’s disease. It demonstrated that hypoxia—when the brain is deprived of oxygen—caused the same selective degeneration of neurons that characteristically die in dementia.”

Coulson says the next step would be to determine what levels of hypoxia result in brain degeneration in humans.

“We couldn’t fit CPAP to mice, but we experimentally prevented the hypoxia and this stopped the cognitive impairment and neuron death, and also reduced the Alzheimer’s pathology,” Coulson says. “This suggests that CPAP treatment of obstructive sleep apnea has the potential to reduce dementia risk.”

The findings could change the way dementia clinicians diagnose and treat their patients, she says.

“Thirty percent of people with obstructive sleep apnea being fitted for CPAP machines already display signs of dementia-like cognitive impairment,” she says. “Unfortunately the hospital system isn’t referring those people to dementia clinics. Some dementia clinicians have reported their patient’s memory has improved after their sleep problems were identified and treated.”

Not everyone with obstructive sleep apnea will get dementia, “but we need to define the ‘at risk’ population,” Coulson says.

“Early-stage human trials are underway with sleep clinicians in Brisbane and Sydney to determine the correlation between hypoxia and sustained cognitive impairment, and whether CPAP can reduce dementia risk.

“I would strongly recommend anyone with obstructive sleep apnea use a CPAP machine to maintain cognitive function, as well as assist with other health issues.”

The study has been published in Nature Communications.

Photo 187465996 © Pop Nukoonrat |