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Disturbed Sleep Cycles Linked to High Risk of Stroke

A new study conducted by Vyoma Shah, Raphael Vallat, Matthew Walker from the University of California at Berkeley and a team of researchers looks at the association between disturbed sleep cycles and the higher risk of developing a condition known as atherosclerosis and concludes that constant disruptions in sleep can significantly increase the risk of having a stroke due to atherosclerosis in the long run.

Atherosclerosis is a heart-related condition characterized by the build-up of fatty substances, cholesterol, and plague in the arteries of a person. Often, the issue can lead to bursting of arteries which may result in the formation of a clot, thereby paving the way for irreversible effects on the health and even potentially fatal cardiovascular events.

In the new research, whose findings appear in the journal PLOS One, the team found that atherosclerosis can only increase the risk of having heart problems in the future but can also elevate the chances of having a stroke because of its impact on inflammation levels in the body.

This means that the disturbed sleep cycles can harm the health of the person in the long run in multiple ways ranging from having serious heart-related conditions and cardiovascular events to having a stroke.

To investigate whether poor sleep and atherosclerosis increased the risk of having a stroke due to changes in inflammation signaling in the body, the researchers assessed and tested disruptions in sleep using actigraphy, which is a process that measures movements done during the night via the use of a device usually worn on the wrist by patients as well as lab-based sleep polysomnography.

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After doing so, it was discovered that disruption in the sleep examined through actigraphy showed higher coronary artery calcium, which is usually regarded as an early symptom of atherosclerosis along with a higher neutrophil count.

The researchers then used mediation analysis in order to further examine the association between sleep disruption, higher levels of calcium in the arteries, and an increase in neutrophil count.

By using the statistical analysis, it was found that the impact of a disturbed sleep cycle on calcium levels in the arteries was primarily because of a higher neutrophil count.

More precisely, the researchers noted that disturbed sleep cycles led to an increase in neutrophil count, which then led to higher coronary artery calcium and hence the development of atherosclerosis.

The results remained the same even after the team adjusted and looked out for other possible known risk factors of artery disease such as body mass index, older age, blood pressure, sex, smoking habits, ethnicity, underlying conditions, and many more.

Read on the association between sleep duration and heart disease here.

By using polysomnography, the researchers also had similar results although they did not remain after adjusting for some of the contributors to artery disease. However, the team explained that the slight difference in the results of using both of the two methods is due to differences in time periods.

Polysomnography is done only for a single night while the procedure of actigraphy is usually done for up to seven days.

In addition to these findings, the researchers also found no link between the self-reported quality of sleep by the participants and an increased risk of atherosclerosis or having a stroke, which shows self-reporting is not a reliable method when assessing sleep cycles and their contribution in heart disease.

The researchers concluded by saying that the findings show the need for awareness for the effects of disturbed sleep cyles on health. Improving sleep patterns can not only lower the levels of inflammation in the body but also cut down the risk of heart disease and stroke in the future.