Heart complications have become highly prevalent in recent years. Of these complications, heart attacks are the most common; and, in many people, they occur in the early morning hours. New research, published in the Blood November issue, reveals the role of the body’s circadian rhythms in morning heart attacks and ischemic strokes. The research was conducted by Oregon Health and Science University and Brigham and Women’s Hospital.
Causes of increased cardiovascular complications in the morning could either be linked to the body’s clockwork or physical activities associated with morning hours. The research set out to find which the culprit was. Twelve healthy adult participants were monitored continuously for two weeks at the Brigham and Women’s Hospital.
The participants were assigned to a protocol that was designed to separate behavioral and environmental aspects from the natural circadian rhythm of the body.
The researchers monitored the level of plasminogen activator inhibitor-1, or PAI-1, in the body. PAI-1 is known for its inhibition of the breakdown of dangerous blood clots in the body. It is, therefore, a major contributor to heart attacks and strokes. The higher the level of PAI-1, the higher the risk of cardiovascular complications.
A peak of PAI-1 was observed to occur in the morning at around 6:30 a.m. – the same period as which most heart attacks and ischemic strokes occur. This was despite the lack of the usual morning behavioral and environmental conditions, thus showing that the body’s clock system is responsible for the sharp morning rise in plasminogen activator inhibitor-1, and, by extension, the increased risk of heart complications.
Steven Shea, director of the Oregon Institute of Occupational Health Sciences, believes that the research findings would prove helpful in the fight against cardiovascular diseases. He, however, says that further research will be needed to determine which individuals (e.g. obese persons or those suffering from diabetes or a cardiovascular disease) are more vulnerable.
By Isaac Mathu