It’s long been known that chronic psychological stress can influence heart health. Now, a new study finds evidence of key gender differences in the effects of mental stress on the heart.
The research team, led by Dr. Zainab Samad, assistant professor of medicine at Duke University Medical Center in Durham, NC, published their new findings in the Journal of the American College of Cardiology.
Stress is a normal part of life and is vital for evolutionary purposes. The body is programmed to react to life-threatening stress (“The house is on fire!”) with a “fight-or-flight” response, in which the brain triggers a cascade of chemicals and hormones that speed the heart rate, quicken breathing, increase blood pressure, and boost the amount of energy (sugar) supplied to muscles.
Unfortunately, the body does a poor job of discriminating between grave, imminent dangers and less momentous ongoing sources of stress, such as financial difficulties, job strain, and even worries about potential problems that haven’t yet arisen. When the fight-or-flight response is chronically in the “on” position, the body suffers.
Past research indicates that chronic mental stress triggers inflammation, a known instigator of heart disease, but the stress-inflammation-heart disease connection has not yet been fully explained. Additionally, stress may indirectly affect heart health through its influence on dietary patterns, physical activity, and unhealthy coping behaviors such as smoking or drinking alcohol.
In the new study, Dr. Samad and her team analyzed 310 participants – 56 women and 254 men – who were being treated for heart disease and who were part of the Responses of the Mental Stress Induced Myocardial Ischemia to Escitalopram Treatment (REMIT) study.
As part of the study, all participants were required to take part in three tasks that induced mental stress: a mental arithmetic test, a mirror tracing test and an anger recall test. They then took part in an exercise test requiring them to run on a treadmill.
During each task and in rest periods between tasks, subjects’ blood pressure and heart rate were measured, blood samples were taken and any heart changes were monitored through an echocardiogram.
Gender-differing effects of mental stress on heart ‘should be considered in treatment’
After analyzing participants’ physiological responses, the researchers found that the effects of mental stress on the heart varied significantly between men and women.
Specifically, women exposed to mental stress were more likely than men to experience myocardial ischemia – reduced blood flow to the heart as a result of a blockage in the arteries. Stressed women also had higher incidence of platelet aggregation – the early formation of blood clots. Mental stress also induced more negative emotions and fewer positive emotions in women than men. However, men demonstrated more changes in blood pressure and heart rate than women in response to mental stress.
“The relationship between mental stress and cardiovascular disease is well known. This study revealed that mental stress affects the cardiovascular health of men and women differently,” says Dr. Samad. “We need to recognize this difference when evaluating and treating patients for cardiovascular disease.”
The researchers note that further studies are warranted to better understand how the effects of mental stress on the heart differ by sex, particularly the long-term effects.
“This study also underscores the inadequacy of available risk prediction tools, which currently fail to measure an entire facet of risk, i.e. the impact of negative physiological responses to psychological stress in both sexes, and especially so among women,” adds Dr. Samad.
The good news is that many of these harmful effects can be mitigated with simple lifestyle changes: research shows that eating a healthy diet, exercising, and getting enough sleep may slow down cellular aging processes triggered by chronic mental stress.