New research published in Arteriosclerosis, Thrombosis and Vascular Biology Indicates that mental stress has a greater effect on peripheral vessels in women than in men. The additional constriction of blood vessels seen in women may increase their risk of heart-related events and death.
Stress is a normal part of life and our body has a range of responses designed to help us react accordingly. These include physical, mental and emotional adjustments intended to be a positive reaction to keep us alert and ready to avoid danger. However, with the ever-increasing challenges of life today, some people experience a continuous stress response that can have negative consequences.
One of the common physiological responses to mental stress is constriction of peripheral blood vessels to free up more blood to support increased activity in the brain. In healthy people, this increases alertness and concentration. However, if a person has heart disease the constriction of peripheral blood vessels can also result in less blood reaching the heart, which can cause cardiac ischaemia. Previous research reported that stress-induced reduction in cardiac blood supply was more common in women aged <50 years compared with men and older women.
The Mental Stress Ischemia Mechanisms Prognosis study was designed to evaluate the extent of the effects of stress-induced vasoconstriction.
Dr Viola Vaccarino, professor of epidemiology and medicine at Emory University's Rollins School of Public Health in Atlanta explained "This research is important because previous studies have shown that a reduction in blood supply to the heart (ischaemia) during mental stress doubles the risk of heart attack or death from heart disease. This increased risk of adverse cardiovascular events is about the same level as that seen in people who develop reduced blood flow in the heart muscle during a conventional test, such as a treadmill stress test."
During the study of 678 patients with coronary artery disease, the constriction of tiny arteries supplying blood to the fingers was measured using myocardial perfusion imaging and heart rate and blood pressure recorded before and during a public speaking stressor.
The results showed that in women the reduced blood supply to the heart observed during mental stress was a consequence of constriction of peripheral blood vessels. In contrast, in men it was an elevation in blood pressure and heart rate during mental stress that led to a reduction in blood supply to the heart.
Vaccarino commented "Our findings in the peripheral circulation also could reflect what occurs in the arteries in the heart. Instead of dilating and increasing blood flow to the heart during stress, in women the tiny blood vessels are constricted, leading to areas of reduced blood flow. Constriction of peripheral vessels can also induce ischemia in the heart indirectly, because the heart has to pump against increased resistance."
This research highlights the importance of finding effective means of combating mental stress, such as relaxation techniques and physical exercise, especially among people with heart disease. Furthermore, the observed gender differences suggest that health professionals need to pay particular attention to the burden of mental stress among their female patients with heart disease.
Future research will examine whether these cardiovascular responses to mental stress are reflected in an increased incidence of heart attacks or other indicators of worsening heart disease.