More targeted sleep apnea therapies needed to combat cognitive decline

Key Points:

• The study recorded the sleep patterns of more than 470 men aged 41-87 years alongside their daytime cognitive function for processing speed, visual attention, episodic memory recollection and other markers
• Measuring distinct features of brain electrical activity during non-REM sleep, called ‘sleep spindles’, the study aimed to explore if these features can serve as markers of cognitive function
• Standard clinical tests for obstructive sleep apnea may detect and help to improve the disorder with interventions such as continuous positive airway pressure (CPAP) or specific dental devices, the condition does vary between people depending on age and other factors

Flinders University experts have called for long-term research and improved methods to prevent the effects of obstructive sleep apnea (OSA) on cognitive decline.

Researchers explored the heightened risk of cognitive function decline from undiagnosed OSA – particularly in middle-aged men in the community – in one of their latest studies published in Sleep Health Journal. The results show a link between the sleep disorder and cognitive decline and will help formulate better solutions to treat OSA and the subsequent cognitive decline associated with it.  

“Non-REM sleep includes light stage 1 and 2 sleep, as well as deeper stage 3 sleep which is thought to play an important role in learning and memory,” said Flinders University sleep researcher, Doctor Jesse Parker. 

“The presence and severity of OSA was an important factor in this relationship.”  

In 2020, a study collaboration between Australian and Icelandic researchers confirmed the long-suspected link between sleep apnea and the development of Alzheimer’s disease.

The study’s lead investigator, Professor Stephen Robinson, said “The connection is there but untangling the causes and biological mechanisms remains a huge challenge”.

The Flinders Health and Medical Research Institute Sleep Health researchers of the Sleep Health Journal study recommend long-term investigations into sleep spindle phases and OSA to improve future treatments – and to determine whether OSA interventions such as CPAP do improve sleep quality and cognitive function.  

“Highlighting the need for better treatments, our latest studies not only make more links between sleep disorders and poor health outcomes but also the need for tailored specific treatments for individual cases, including co-occurring conditions such as insomnia and sleep apnoea.

“Along with uncontrolled hypertension, this latest study also clearly links cognitive function to sleep in adult males, possibly made worse by undiagnosed moderate to severe OSA,” said senior author Associate Professor Andrew Vakulin.