A sleeping time bomb

Lack of sleep is linked to high cholesterol, obesity and depression. Now researchers say it can damage your brain. Researchers from RMIT and University of Iceland are examining how sleep disorders could damage the brain.

Two leading European researchers in sleep and respiratory disorders have joined RMIT University in a collaborative study to investigate links between Alzheimer’s disease and obstructive sleep apnoea (OSA).

Professor Thorarinn Gislason and Professor Bryndís Benediktsdóttir, a husband and wife team from the University of Iceland, have given RMIT access to their samples of brain tissue from people who died from OSA – believed to be the only collection of its kind in the world.

The high-profile duo will be based at the Bundoora campus during February where they are working with Professor Stephen Robinson from the School of Health Sciences on the long-term project.

“Recent literature indicates that the incidence of sleep apnoea may be up around the 80% mark in patients with Alzheimer’s disease, although in many cases, it is undiagnosed and untreated,” Professor Robinson, Deputy Head of School (Research and Innovation), said.

“We are looking for evidence that OSA might cause Alzheimer’s disease-like changes in the brain.”

Obstructive sleep apnoea is a dangerous – and sometimes fatal – sleep disorder which causes the soft tissue in the back of the throat to collapse throughout the night, blocking airways and cutting air supply.

Sufferers can stop breathing for up to 30 seconds while they are sleeping and they often wake gasping for air.

It is believed that one in five people have some degree of the disorder. Yet many are unaware they suffer – blaming poor quality sleep for leaving them tired, irritable and depressed.

“Official estimates put the figure at about five per cent of the population but some researchers are saying that it’s grossly underestimated and the incidence is really between 10% and 20%, particularly in midlife,” Professor Robinson said.

Recent research shows that sleep apnoea can cause far more serious problems beyond daily difficulties with focus, attention and grumpiness that comes with lack of sleep.

Professor Robinson said that untreated sleep apnoea was also a big contributor to diabetes, hypertension and cardiovascular disease – significantly increasing risk of heart attack and stroke.

“The indications are that if you have OSA in midlife you have a higher chance of developing Alzheimer’s disease in later life and we are trying to understand why that is,” he said.

As part of the collaborative study, the team will build on the samples from 60 patients already available, to closely look at how the sleep disorder can damage the brain and accelerate the degenerative process.

It is hoped the long-term project will grow to include samples from several hundred patients.

While it has long been believed that obesity is the major contributing factor in developing OSA, Professor Robinson said OSA affected people of all ages.

People over 50 are more likely to develop the condition but it can occur in children with developmental disorders, with about 80% of children with Down Syndrome being affected.

It also affects twice as many men than women.

Research also links OSA to night sweats, insomnia, restless legs syndrome, bruxism (teeth grinding), nocturnal gastro-oesophageal reflux and asthma-like symptoms.

(Source: RMIT)