A new study found that women who rate their jobs as highly demanding and stressful were at an increased risk of heart attack, stroke or dying from heart disease.
Heart disease is one of the leading killers of both men and women, and scientists have identified stress as one major risk factor that can damage the heart. But Dr. Michelle Albert, one of the study's authors, said most of the previous research on stress and strain at work has focused on how they affect men's hearts.
"We're all stressed out, but we're talking about strain or stress that's above and beyond the body's ability to handle it," Albert said.
Albert and her colleagues at Brigham and Women's Hospital in Boston studied more than 22,000 women in the health care field – nurses, doctors and other professionals who were part of the decade-long Women's Health Study. The researchers asked women about the stressors in their jobs, including the pace, amount of work, demands, required skills and control over decision-making.
In the study published today in the journal PLoS One, Albert and her colleagues found that the women who said their jobs were highly demanding and stressful were 38 percent more likely to have a heart problem than women who reported low job strain.
Though only a few previous studies of job stress and heart health have focused on women, researchers have had mixed results on establishing a link. One major trial, the Nurse's Health Study, followed 35,000 female nurses over four years and found no relationship between coronary heart disease and job strain. On the other hand, a recent study of nearly 50,000 women in Finland found that active jobs were linked to an increased risk of stroke.
But Dr. Susan Bennett, co-director of the Women's Heart Health Program at the MedStar Heart Institute in Washington, D.C., said scientists are becoming more assured that job strain has definite impacts on health.
"We know that stress is a killer. It's just very hard to pour it into a beaker and measure how it affects people," Bennett said.
There are many possible ways that chronic stress can contribute to heart disease, even by causing physical harm to cardiovascular system. High levels of stress hormones can lead to heart risk factors such as higher blood pressure, a build-up of plaque inside the arteries and increased insulin resistance.
Stressed people may also be more likely to smoke, drink excessively, or have poor eating and sleeping habits, all of which have been associated with heart problems. Also, some studies have found links between heart and mental health woes, such as depression and anxiety. But Albert noted that only up to 26 percent of the relationship between job strain and cardiovascular disease could be explained by traditional heart risk factors like these.
The study had a few problems that make it difficult to generalize the findings to a larger group of women. First, the study interviewed mostly white women, all of whom worked in the health care industry, so the results don't capture how job stress affects women of all races and ethnicities or in other occupations.
The study also asked women about their job stress only once during the 10 years of the study, making it difficult to judge how their stress might have affected them over time.