Study finds impact of sleep-disordered breathing in adults over 70

May 31, 2022

A study of data from the Australian-first ASPREE sub-study, SNORE-ASA, found sleep-disordered breathing (SDB) is linked to lower physical health-related quality of life, and slightly lower cognitive (thinking and memory) function in older adults.

SDB is a broad term for breathing difficulties that happen during sleep and can range from loud snoring to sleep apnoea, in which breathing stops for a period of time.

Researchers analysed data from 1399 Australian ASPREE participants who enrolled in SNORE-ASA (The Study of Neurocognitive Outcomes, Radiological and Retinal Effects of Aspirin in Sleep Apnoea) sub-study. Participants had not been diagnosed with sleep apnoea (or used CPAP, the major means of treating sleep apnoea). They wore a portable sleep apnoea device in their own homes overnight and underwent additional cognitive exercises. Some participants also had an MRI and retinal imaging.

Researchers found:

  • 81% of SNORE-ASA sub-study participants unknowingly had some degree of SDB
  • More men than women had moderate to severe SDB (36% of men and 25% women).
  • Just over 7% of men and almost 6% of women with SDB reported significant daytime sleepiness
  • Those with SDB had overall poorer concentration and memory compared to those who did not have SDB, but the differences were very small.
  • Participants with SDB also reported having a lower physical quality of life.
  • There was no link between SDB and depression or SDB and daytime sleepiness.

SNORE-ASA lead researcher Dr Stephanie Ward, is a practising geriatrician completing her PhD at Monash University School of Public Health and Preventive Medicine. She also consults on the ABC hit series ‘Old People’s Home for 4Year Olds’ and the follow up ‘Old People’s Home for Teenagers’.

Above: Dr Stephanie Ward led the ASPREE SNORE-ASA sub-study.

Dr Ward said this study looked at associations between SDB and health measures that are important for older people, including mood, daytime sleepiness, quality of life, and cognitive function.

“SDB is so common as we get older. Understanding to what degree SDB matters to an older adult’s health and wellbeing is important.” Dr Ward said.

There is increasing recognition of the important role of sleep for brain health, especially as sleep has been shown to be integral to the clearance of neurotoxins. In SDB, not only may sleep be interrupted, repeated drops in blood oxygen levels that result from the SDB may affect blood vessel health in the brain.

Dr Ward said SDB had not been definitively established as a risk factor for dementia.

“SDB may be a risk factor for developing dementia as we get older, but we don’t know. We already know about many other risk factors for dementia, such as being physically inactive, socially isolated, having a hearing impairment, hypertension and obesity. The results of this study do confirm an association of SDB with mildly lower cognitive function, but, whether SDB increases the risk of decline in cognition over time, and importantly, whether treatment of SDB prevents dementia, remains to be seen,” said Dr Ward.

SNORE-ASA investigators advised GPs of their patient’s home-based sleep study readings for follow-up care.

Further analyses of SNORE-ASA data are underway.

In summary

  • The study shows how common the disorder may be in healthy older adults, who were unaware they had the condition.
  • This study is an important step to better understand the role of SDB in health as we age. It is the first study to link SDB with lower physical quality of life in older age.
  • More research is needed.  SNORE-ASA sub-study investigators will further analyse the data, including to understand how SDB may affect health over a period of time.

The study, ‘Sleep-disordered breathing was associated with lower health-related quality of life and cognitive function in a cross-sectional study of older adults’, is published in the journal Respirology.

This post was adapted from a Monash University news item.

Updated 12.09.2022 to include 'Old People's Home for Teenagers' 

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