Research reveals artery calcification more common in night owls
A new study published in the journal Sleep Medicine has found that individuals who identify as extreme evening types or night owls are more likely to have artery calcification compared to those who are extreme morning types. Artery calcification is a key factor in the development of atherosclerosis, a condition in which fatty deposits accumulate on the inside of the arteries, restricting blood flow and increasing the risk of cardiovascular disease.
The study, conducted by researchers at Sahlgrenska Academy, University of Gothenburg, involved 771 participants aged between 50 and 64 who were part of the larger population study SCAPIS. The degree of artery calcification in the heart’s coronary arteries was assessed using computer tomography scans. Participants were also asked to indicate their chronotype, or preference for morning or evening activities, on a five-point scale.
Among the participants, 144 identified as extreme morning types while 128 identified as extreme evening types. The results revealed that individuals who were most alert and active in the morning had the lowest prevalence of artery calcification, with only 22.2% showing pronounced calcification. On the other hand, the extreme evening type group had the highest prevalence of severe coronary artery calcification, with 40.6% exhibiting significant calcification.
Lead author Mio Kobayashi Frisk, a doctoral student at Sahlgrenska Academy, highlighted the implications of the study’s findings:
Our results indicate that extreme evening chronotype may be linked not only to poorer cardiovascular health in general but also more specifically to calcification in the coronary arteries and atherosclerosis.
The researchers took into account various factors that could influence the risk of atherosclerosis, including blood pressure, blood lipids, weight, physical activity, stress level, sleep quality, and smoking. Despite these adjustments, the influence of circadian rhythms on artery calcification remained significant.
Ding Zou, a researcher at Sahlgrenska Academy and the last author of the study, emphasized the importance of considering circadian rhythms in the prevention and treatment of cardiovascular diseases:
As well as the previously known factors, the individual circadian rhythm also appears to be an important risk factor for atherosclerosis. We interpret our results as indicating that circadian rhythms are more significant early in the disease process. It should therefore particularly be considered in the preventive treatment of cardiovascular diseases.
It’s worth noting that the study excluded individuals who had experienced a heart attack, which means that the participants may have been healthier than the general population. In addition, the researchers acknowledged that self-reported chronotypes may introduce some bias into the study.
The findings of this research add to the growing body of evidence highlighting the impact of sleep and circadian rhythms on cardiovascular health. Adopting healthier sleep practices and addressing individual chronotypes may play a crucial role in reducing the risk of artery calcification and related cardiovascular diseases.
The SCAPIS study, which stands for Swedish CArdioPulmonary bioImage Study, is a comprehensive research project focused on cardiac, vascular, and pulmonary diseases. It involves 30,000 randomly selected Swedes aged 50-64 who have undergone extensive health examinations including blood sampling, functional tests, and advanced imaging of organs and blood vessels.
This research sheds light on the importance of considering circadian rhythms and sleep patterns in the prevention and management of cardiovascular diseases. Identifying and addressing individual chronotypes could potentially lead to better outcomes and improved cardiovascular health.
