Job Pressure Raises Risk of Ischemic Heart Disease in Women
By Megan Brooks
Medscape Medical News
May 10, 2010 — Female nurses who feel they are under "too much" pressure at work have a significantly increased risk of developing ischemic heart disease (IHD), independent of traditional coronary risk factors, according to new findings from the prospective Danish Nurse Cohort Study reported in the May issue of Occupational and Environmental Medicine.
"This study adds to the previous body of evidence suggesting harmful effects of excessive psychological demands at work on cardiac health but is one among very few that demonstrates the effect among women," write Karen Allesoe, from Research Centre for Prevention and Health, Glostrup University Hospital, Denmark, and colleagues.
The study included 12,116 female nurses who were between 45 and 64 years old in 1993 (median age, 51 years) and actively employed when they completed a questionnaire on health and lifestyle, including occupational status and working conditions.
The researchers focused their analyses on answers to 1 question on level of work pressure (too low, suitable, a little too high, or much too high) and 1 question on level of job influence (major influence, a certain influence, or minor or no influence).
During a 15-year follow-up period, there were 580 incident cases of IHD. This included 369 cases of angina pectoris, 138 myocardial infarctions, and 73 "other" IHD events.
According to the investigators, in the fully adjusted model, nurses who reported work pressure to be "much too high" — about 60% altogether — had a 1.4-fold increased risk of incident IHD (hazard ratio, 1.38; 95% confidence interval, 1.04 – 1.81).
Age-stratified analysis showed that the association between high work pressure and IHD was only significant among nurses younger than 51 years at baseline.
"Having work pressure that was much too high was a significant predictor of IHD even when angina pectoris was excluded both in age-adjusted analyses and when controlling for traditional cardiovascular risk factors, shift work, and physical activity at work," the investigators note.
"Additional work should be carried out to identify factors contributing to the perceived high work pressure," they conclude.
No significant association was found between job influence and IHD.
According to investigators, the study had sufficient statistical power given the size of the cohort and number of IHD cases that occurred during follow-up. Other strengths are the high response rates obtained in this cohort of Danish nurses, the validity of the self-reported information provided by the nurses, the fact that the study was based on the entire population of Danish nurses, and the use of a nationwide hospital register to identify IHD cases.
The fact that the findings are based on only 2 questions regarding work "exposures" means that important aspects, especially of the work control or influence, may have been overlooked. This also makes comparison with other studies difficult, they note.
Nonetheless, they say these findings "should be taken into account in the planning of primary prevention."