May 5, 2010 -- Too much pressure at work could be a significant risk factor for ischemic heart disease among younger female employees, according to a new study from Denmark.
Ischemic heart disease occurs when blood flow is restricted to the heart muscle. Often called "a silent killer," it is estimated that as many as 4 million Americans may have ischemic episodes and not be aware that they have this condition because they do not experience symptoms.
Previous research has linked workplace stress and job strain to heart disease risk, but many of those studies focused on men.
Reporting in the May 6 issue of Occupational and Environmental Medicine, researchers at Glostrup University Hospital in Denmark looked at more than 12,000 female employees aged 45 to 64 who were part of the Danish Nurse Cohort Study and were followed for 15 years, from 1993 to 2008. The median age of the participants was 51.
The nurses filled out questionnaires about health, lifestyle, and occupation. The researchers took into account factors including work pressure, psychosocial work environments, job influence, occupational characteristics, such as the level of physical activity performed while on the job, and biological and behavioral factors such as smoking, body mass index, drinking alcohol, and family history of disease.
Sixty percent of the nurses interviewed said work pressure was much too high or a little too high. Over the course of the study, 580 women were admitted to the hospital for ischemic heart disease; among those women, 369 cases were angina, 138 were heart attacks, and 73 were other cases of ischemic heart disease.
Among the study results:
- Nurses who said their work pressure was much too high had a nearly 50% increased risk of ischemic heart disease compared with women who reported a manageable work pressure. After taking into account other risk factors for heart disease such as smoking and lifestyle, the risk fell to 35%.
- Nurses who reported work pressure being a little too high had a 25% increased risk.
- There was no significant increased risk of ischemic heart disease among nurses who reported minor or no influence on the job.
- Age was a major factor; when researchers analyzed the findings by age, only nurses younger than 51 were at significant risk of heart disease.
"It seems as if the effect of work pressure has a greater impact on younger nurses," researchers write. "This is in agreement with findings from previous studies looking at age specific effects in both men and women. The lower risk among the older nurses may be due to other risk factors that become relatively more important with increasing age. Furthermore, vulnerable individuals may have [already] left work."