How stress increases stroke and heart attack risk

Researchers have shown that anger, anxiety, and depression not only affect the functioning of the heart, but also increase heart disease risk.

Stroke and heart attacks are the end products of progressive damage to blood vessels supplying the heart and brain, a process called atherosclerosis.

Atherosclerosis progresses when there are high levels of chemicals in the body called pro-inflammatory cytokines.

It is thought that persisting stress increases the risk for atherosclerosis and cardiovascular disease by evoking negative emotions that, in turn, raise the levels of pro-inflammatory chemicals in the body.

Researchers have now investigated the underlying neural circuitry of this process, and report their findings in the current issue of Biological Psychiatry.

To conduct the study, Dr. Peter Gianaros, Associate Professor at the University of Pittsburgh and first author on the study and his colleagues recruited 157 healthy adult volunteers who were asked to regulate their emotional reactions to unpleasant pictures while their brain activity was measured with functional imaging.

The researchers also scanned their arteries for signs of atherosclerosis to assess heart disease risk and measured levels of inflammation in the bloodstream, a major physiological risk factor for atherosclerosis and premature death by heart disease.

They found that individuals who show greater brain activation when regulating their negative emotions also exhibit elevated blood levels of interleukin-6, one of the body's pro-inflammatory cytokines, and increased thickness of the carotid artery wall, a marker of atherosclerosis.

The inflammation levels accounted for the link between signs of atherosclerosis and brain activity patterns seen during emotion regulation. Importantly, the findings were significant even after controlling for a number of different factors, like age, gender, smoking, and other conventional heart disease risk factors.

The study has been published in the journal Biological Psychiatry.