SUNDAY, Nov. 14 (HealthDay News) -- Women who have taxing jobs with little control over their busy days are at higher risk for heart attacks or the need for coronary bypass surgery, new research suggests.

Furthermore, worrying about losing one's job also raised the odds of having cardiovascular disease risk factors such as high blood pressure and higher cholesterol levels -- but not actual heart attacks, stroke or death, the researchers said.

The study, presented Sunday at the annual meeting of the American Heart Association in Chicago, breaks new ground for being one of the first to look at the effect of work-related stress on women's health. Most previous studies have focused on men and, yes, those studies found that job stress upped males' odds for cardiovascular disease, too.

Women comprise roughly half of the U.S. workforce today, with 70 percent of all women holding some kind of job, said study senior author Dr. Michelle A. Albert, an associate physician at Brigham and Women's Hospital in Boston.

Albert and her colleagues looked at more than 17,000 female health professionals, with an average age of 57, who showed no signs of cardiovascular disease at the beginning of the study.

Participants responded to statements about how draining their job was, such as -- "My job allows me to make a lot of decisions on my own" or "My job requires that I learn new things" or "My job requires working very fast."

"Job strain [involving] psychological demand and decision latitude are tied into the concept of skill, how you are allowed to be at your job, is your job repetitive, does it require you to work at a fast pace," explained Albert.

Over 10 years of follow-up, the researchers noted that women with high job strain -- demanding jobs over which they had little control -- were more likely to be sedentary and to have high cholesterol. They were also at almost double the risk for a heart attack and at a 43 percent higher risk to undergo a bypass procedure. The researchers found no significant link between job strain and either stroke or risk for death.

Women with job insecurity (fear of job loss) were not more likely to have a heart attack or other event, but they were more likely to have several risk factors for cardiovascular problems, including physical inactivity, high cholesterol, hypertension or diabetes. They were also more likely to weigh more.

When it came to health, how demanding a job was seemed to trump how free women were to make decisions or to use their creativity.

"In our particular cohort of female health professionals, the 'demand' component of this model appeared to be driving the vascular risk and less so the control factor," Albert stated.

Dr. Suzanne Steinbaum, director of Women and Heart Disease at Lenox Hill Hospital in New York City, said: "This is the first time that we are seeing the realities of the fact that women are in the workforce just as much as men but oftentimes are not in a position of management. And it's not just necessarily working but the nature of what the job is like."

It should be noted that this study highlighted an apparent association between job stress and heart trouble for women, and did not prove a cause and effect.

A second study, also presented at the meeting, found that, if you're a woman, there may be such a thing as sleeping too long, although perhaps not sleeping too little, when it comes to heart health.

Researchers at the Harvard School of Public Health tracked the sleep habits and stroke incidence of almost 70,000 women for 20 years.

They reported that women who slept for 10 hours or more had a 63 percent higher risk of suffering a stroke, and a 55 percent hiked risk when other factors such as blood pressure were taken into account. Women who slept seven hours -- the median amount of sleep reported in the study -- had the lowest risk of stroke.

Short sleep duration didn't seem to matter: Even women who slept six or fewer hours a night were not at heightened stroke risk, the researchers reported.

Previous research had suggested the opposite, the research team noted.

More information

There's more on women and heart disease at the American Heart Association.