Everyone needs sleep - without it we risk high cholesterol, obesity and depression - but new research shows missing sleep may do long-term damage to the brain as well.

Australian and international authorities on snoozing have joined forces to investigate the links between Alzheimer’s disease and obstructive sleep apnoea (OSA).

Many studies are conducted by several institutions in conjunction, but this one is little bit different.

A husband-and-wife duo of Icelandic professors has allowed RMIT researchers access to their unique collection – dozens of samples of brain tissue from people who died from OSA.

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

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

“We are looking for evidence that OSA might cause Alzheimer's disease-like changes in

“Recent literature indicates that the incidence of sleep apnoea may be up around the 80 per cent mark in patients with Alzheimer’s disease, although in many cases, it is undiagnosed and untreated.”

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

OSA remains a mysterious and widespread condition. Originally considered an effect of obesity, 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.

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

Professor Thorarinn Gislason and Professor Bryndís Benediktsdóttir, the team from the University of Iceland will speak about a wide range of sleep disorders while they are in Australia – from restless leg disorder to sleepwalking and night terrors – at a seminar for RMIT students and staff.