Sleep apnoea-Alzheimer’s link probed

Over the past few years there have been a number of studies that have fingered sleep apnoea as a potential cause of dementia. Now a major clinical trial launched by the Queensland Brain Institute (QBI) is set to discover whether treatment can reduce the risk.

Sleep apnoea is caused by sporadic collapse of the upper airway, which leads to pauses in breathing and the development of hypoxia – low blood oxygen levels.

As early as 2011, a team from the department of psychiatry at the University of California, San Francisco, in the US, identified sleep-disordered breathing – in this case, in older women – as associated with “increased risk of developing cognitive impairment”.

A meta-analysis published in 2016 came to some startling conclusions. Patients with Alzheimer’s disease were five times more likely than baseline to have sleep apnoea. Half of all people with Alzheimer’s had experienced sleep apnoea at some point.

The condition, the researchers concluded, “may further aggravate AD progression”.

Standard treatment for sleep apnoea is mechanical – the use of a continuous positive airway pressure (CPAP) ventilator.

Researchers at the QBI want to discover whether CPAP treatment also lowers the risk for developing Alzheimer’s. To find out, they are enrolling patients aged between 55 and 75.

“Sleep disturbances can occur up to 10 years prior to Alzheimer’s disease,” says QBI director, Pankaj Sah.

“Considering that Alzheimer’s affects roughly one-third of the elderly population, this important research may inform preventative public health measures in the future.”