So-called night owls, i.e. people who go to bed late, have a significantly higher risk of hardening of the arteries than early risers. This also increases your risk of a heart attack or stroke.
A new study involving experts from the University of Gothenburg examined the connection between the present chronotype and coronary artery calcification. The results were published in the specialist journal “Sleep Medicine”.
Participants assess their chronotype themselves
The study included a total of 771 participants between the ages of 50 and 64. They were instructed to assign themselves to one of five different chronotypes: extreme morning type, moderate morning type, medium type, moderate evening type or extreme evening type.
The team then examined the degree of arteriosclerosis in the participants’ coronary arteries using computer tomography.
What is a Chronotype?
The term chronotype refers to a person’s individual biological clock and describes whether someone is, for example, a morning person (early riser) or a night owl (person who goes to bed late) – i.e. which sleeping and waking times are preferred.
Among the participants, a total of 144 people identified themselves as extreme morning types and a further 128 people saw themselves as extreme evening types, the researchers report.
Hardening of the arteries is less common in morning people
The data analysis showed that in the group of extreme morning people, 22.2 percent had severe arteriosclerosis, which was the lowest proportion of arteriosclerosis among all five chronotype groups examined, according to the research team.
In contrast, among the participants who belonged to the group of extreme evening types, 40.6 percent were affected by severe arterial calcification, which represented the highest prevalence of severe coronary artery calcification.
“Our results suggest that an extreme evening chronotype may be associated not only with poorer cardiovascular health in general, but also specifically with coronary artery calcification and atherosclerosis,” reports study author Mio Kobayashi Frisk in a press release.
Circadian rhythms are more important at an early stage of the atherosclerosis disease process and should be given special consideration in the preventive treatment of cardiovascular diseases, adds Ding Zou.
Circadian rhythm as a risk factor
The individual circadian rhythm appears to be an important risk factor for atherosclerosis, with arteriosclerosis occurring almost twice as often in night owls compared to people who get up early, the researchers conclude. (as)