(CBS News) Heart disease is the country's No. 1 killer of men and women, taking almost 600,000 lives each year. A new study that looked at stress as a risk factor for heart problems found mental stress can be much harder on a woman's heart compared to a man's.
For the research that was presented this Tuesday at the Federation of American Societies for Experimental Biology's annual meeting in San Diego, Penn State College of Medicine researchers recruited 17 healthy adults, about half of which were female, looking for the effects stress had on the heart's blood flow. Typically when heart rate and blood pressure increase, blood flow to the heart increases so it can pump harder.
The researchers measured heart rate and blood pressure, and used a Doppler ultrasound test to measure blood flow through the heart's blood vessels. They took these measurements at rest, but also took measurements after putting participants through "mental arithmetic" where they were given a random number and asked to sequentially subtract seven. To "stress the sexes," the researchers badgered participants throughout those tests, telling them they were wrong when they weren't or urging them to answer faster.
The study showed that all participants showed an increase in heart rate and blood pressure during the math tasks, but while men increased their coronary blood flow under stress, women showed no change. According to the researchers, pumping less blood through the heart during a stressful situation might cause more strain on women's hearts. Study author Dr. Chester Ray, professor of medicine, and cellular and molecular physiology at Penn State called the findings a surprise since earlier research has showed men reduce blood flow during physical stress from exercising.
"Stress reduction is important for anyone, regardless of gender," he said in a written statement, "but this study shines a light on how stress differently affects the hearts of women, potentially putting them at greater risk of a coronary event."
The findings may partially explain why women are more likely to suffer from "broken heart syndrome," Dr. William O'Neill, executive dean of research at the University of Miami Miller School of Medicine, told WebMD. A study last November found women are up to nine times more likely to experience the "syndrome" that increases risk for heart failure or heart attack-like symptoms in the weeks following a traumatic event.
"Women come into the hospital and look like they have had a massive heart attack, but there is no blockage," O'Neill said. "The message to women is, if they feel discomfort if under extreme stress, they should let their doctor know."
The American Heart Association has more on heart disease in women.