By Margarita Nahapetyan
When women experience mental stress they are more likely than men to suffer heart problems, according to a small new study from the U.S. scientists who revealed that during emotional upsets, heart blood flow increases in men, but never changes in women.
In the United States, coronary artery disease continues to be number one cause of death of both men and women, taking nearly 600,000 lives every year. However, the numbers are not evenly divided between the two genders: significantly more men than women are diagnosed with heart disease every year, and it is not quite clear yet what are the reasons behind this difference. But now, in spite of the fact that some research in this field has previously shown that men's hearts become more constricted than women's during physical activity, letting less blood flow through, the new study claims that mental and emotional stress can be much harder on a woman's heart than on a man's.
For their study, researchers involved seventeen male and female volunteers (a near-equal mix of both genders) and looked for the effects stress had on the blood flow of their hearts. In a typical situation, when blood pressure and heart rate increase, blood flow of the heart increases as well so it can pump harder. In the participants, scientists measured heart rate, blood pressure and used a Doppler ultrasound test in order to measure blood flow through the coronary blood vessels of their hearts.
The measurements were taken in all the subjects at rest and also while they did three minutes of mental math where they were given a series of arithmetic problems in which they had to sequentially subtract seven, starting from a random number. In order to boost the stress levels during performing this task, the investigators urged the participants to do the calculations faster or told them that they gave the wrong answer even when the answer was correct. At the end of the task, all 17 volunteers underwent the same three heart function tests again.
It was revealed that at rest there were very little differences between the results of the three tests in both men and women. During the mental math experiment, all the recruiters showed an increase in heart rate and blood pressure, regardless of gender. However, researchers found that while men showed an increase in coronary vascular conductance under stress, there was no change in women. Dr. Chester Ray, professor of medicine, and cellular and molecular physiology at Penn State, who led the research, said in statement that the findings come as a surprise since previous studies have demonstrated that men have significantly reduced heart blood flow than women during the physical stress from exercising. He added that reduction of stress is critical to any person, regardless of gender, but this new study shows how mental stress differently affects the hearts of women, putting them at higher risk of a heart disease.
According to researchers, these new results of their work highlight the importance of mental/emotional stress on a person's physical health, and could explain why the broken heart syndrome - when the heart muscle is temporarily weakened after stressful events like losing a partner - happens almost only in women. The experts also said that more studies on the matter are needed in order to investigate more thoroughly the mechanism behind this gender difference in the body's response to stress. More research, they explained, could lead to more effective treatments and better prevention efforts for women who are more likely to suffer heart disease.
The findings were presented last week at the Federation of American Societies for Experimental Biology's annual meeting in San Diego.