A normal part of sleep, unconscious wakefulness occurs spontaneously. In part, it is the body’s response to potentially dangerous conditions, including noise or hindered breathing. Other possible triggers are light, temperature, limb movements, pain and trauma.
“A common trigger for nocturnal arousals is obstructive sleep apnoea when breathing stops and the arousal system ensures the activation of our body to change our sleep position and to reopen the upper airway,” Linz said. “Another cause of arousals can be ‘noise pollution’ during the night by, for example, night-time aircraft noise. Depending on the strength of the arousal, a person might become consciously aware of the environment, but often that is not the case. Typically, people will feel exhausted and tired in the morning because of their sleep fragmentation but will not be aware of the individual arousals.”
Study limitations included that the participants were older and mostly white. As such, the findings cannot be extended to include younger men and women or other races. Additionally, it demonstrates a link between greater sleep arousal burden and increased risk of death rather than a direct cause.
“Even though many knowledge gaps on the relationship between sleep and CVD [cardiovascular disease] remain to be studied in the coming years, this study provides solid evidence supporting the importance of sleep quality for a better CV health,” researchers said. “Further evidence combining comprehensive sleep evaluation with biological sampling and long-term follow-ups will be desirable . . . What remains to be determined is whether an intervention aiming at improving sleep quality is able to reduce the incidence of CV events and mortality. While awaiting these trials, we wish you sweet dreams.”