We all wake up occasionally at night. We hear noise – traffic or bird chirp – we roar, there’s a flash of light or a change in temperature. This is what researchers call “cortical arousal” – a short period of unconscious awakening. And, although such mutations affect our heart rate, blood pressure and blood flow (cardiac hemodynamics), they are normal.
But when those nightmares often come, they can become a “burden.”
Researchers studying sleep (polysomnologists) talk about nocturnal “arousal burden”: the burden of getting excited at night.
They have shown that the burden of excitation can disrupt the natural circadian rhythm of the body’s cardiovascular system. And that can lead to higher blood pressure and insulin resistance.
Now, a study of 8,001 people, spread across various test groups, suggests that the burden of arousal and cardiovascular mortality are linked to “all causes” – that is, poor sleep can be fatal.
Cardiovascular diseases (CVDs) are the No. 1 cause of death worldwide. The World Health Organization states that “more people die each year from CVDs than from any other cause.” At the last count, it was 17.9 million deaths from CVDs in a year.
Researchers from Australia, the Netherlands, Denmark and the United States have published the results of a long-term three-part study in the European Heart Journal.
They say the death risks from the burden of excitement come down to the quality of sleep, rather than how long you sleep.
Watching words are “sleep irregularities,” sleep difficulties and “non-standard sleep” – waking up is basically worse than when you went to bed. All that is “associated with an increased risk of mortality, regardless of sleep duration,” they write.
Participants were an older group of people, most of whom had preexisting health conditions.
For example, 40% of women were overweight, 13.7% had diabetes, and 60% had a history of hypertension.
Half of the men had a history of hypertension, 13% had diabetes, and 17% had a history of coronary artery disease.
Limitations of study
The researchers acknowledge the participants’ age and social backgrounds as a limitation in their findings: “All cohorts are predominantly white men and women from middle age to older age. Thus, our findings cannot be extrapolated to other races or younger individuals. ”
On the other hand, it may be useful for the purpose of studying the effect of underlying conditions.
As WHO states: “Most cardiovascular diseases can be prevented by addressing behavioral risk factors such as tobacco use, unhealthy diet and obesity…. People with or at high cardiovascular risk (due to the presence of one or more risk factors such as hypertension, diabetes, hyperlipidaemia or already established disease) need to be identified and managed using counseling and medicines, as appropriate . “
The researchers say that “although the incidence of concussions was lower in women than in men, the association with mortality was stronger in women.”
They also say that they had not considered the effects of any medication the participants took, and their findings were obtained on one night (overnight polysomnography).
They say that there may be day-to-night variations in the burden of excitement among participants, which may have influenced the “strength of connections” with cardiovascular deaths and all causes.
In future studies, the researchers say they could look deeper into the frequency of disturbed sleep and how participants transition from deep sleep to light sleep, with a view to reducing the burden of excitement and the associated overall health risk.