Disjointed sleep can be a health nightmare for women

Most people remember when they wake during the night. But it’s the many briefer moments of stirring from slumber that can dramatically impact health – particularly for women.

One of the issues for most people is they’re not aware of it happening because these moments are known as unconscious wakefulness, and you rarely remember them in the morning.

It’s also known as cortical arousal and is a normal part of sleep. It allows humans to respond to threats like noise or internal concerns like interrupted breathing due to sleep apnoea. But no research exists on the impact of the number and duration of these arousals on health and mortality.

A world-first study led by the University of Adelaide has demonstrated that women who experience regular, ongoing fragmented sleep have nearly double the risk of dying from cardiovascular disease. Those with a high number and longer duration of these arousals had nearly double the risk of dying from cardiovascular disease to women of a similar age across the general population. For men with similar issues, their risk of cardiovascular death increased by just over a quarter compared to the broader male population.

The team was led by Associate Professor Mathias Baumert of the School of Electrical and Electronic Engineering, with Dr Sobhan Salari Shahrbabaki and Professor Susan Redline of Harvard Medical School (USA), and Associate Professor Dominik Linz, University of Adelaide and Maastricht University Medical Center (The Netherlands).

What’s next?

They are now trialling collection of data on when people unconsciously wake through personal fitness trackers and smartwatches. Making it easier to collect this data will be another big step to understand the extent of this sleeping danger and help researchers develop ways to treat it.