Is Improved Deep Sleep the Key to Dementia Prevention?

A study indicates that even a minimal yearly decrease of one percent in deep sleep for individuals aged over 60 leads to a 27% higher risk of dementia. This suggests that preserving or improving deep sleep, also referred to as slow wave sleep, in older age may help prevent dementia (1^✔ ✔Trusted Source
Association Between Slow-Wave Sleep Loss and Incident Dementia

Go to source). The study, led by Associate Professor Matthew Pase, from the Monash School of Psychological Sciences and the Turner Institute for Brain and Mental Health in Melbourne, Australia, and published in JAMA Neurology, looked at 346 participants, over 60 years of age, enrolled in the Framingham Heart Study who completed two overnight sleep studies in the time periods 1995 to 1998 and 2001 to 2003, with an average of five years between the two studies.

Decline in Deep Sleep and Dementia Risk

These participants were then carefully followed for dementia from the time of the second sleep study through to 2018. The researchers found, on average, that the amount of deep sleep declined between the two studies, indicating slow wave sleep loss with ageing. Over the next 17 years of follow-up, there were 52 cases of dementia. Even adjusting for age, sex, cohort, genetic factors, smoking status, sleeping medication use, antidepressant use, and anxiolytic use, each percentage decrease in deep sleep each year was associated with a 27 per cent increase in the risk of dementia.

“However, to date we have been unsure of the role of slow-wave sleep in the development of dementia. Our findings suggest that slow wave sleep loss may be a modifiable dementia risk factor.”

Associate Professor Pase said that the Framingham Heart Study is a unique community-based cohort with repeated overnight polysomnographic (PSG) sleep studies and uninterrupted surveillance for incident dementia.

“We used these to examine how slow-wave sleep changed with ageing and whether changes in slow-wave sleep percentage were associated with the risk of later-life dementia up to 17 years later,” he said.

“We also examined whether genetic risk for Alzheimers disease or brain volumes suggestive of early neurodegeneration were associated with a reduction in slow-wave sleep. We found that a genetic risk factor for Alzheimer’s disease, but not brain volume, was associated with accelerated declines in slow wave sleep.”

Reference:

1. Association Between Slow-Wave Sleep Loss and Incident Dementia - (https://jamanetwork.com/journals/jamaneurology/article-abstract/2810957)

Source-Eurekalert