British civil servants working three to four hours longer than usual per day appear to have an increased risk of having a coronary heart disease event, a prospective cohort study showed.

After accounting for traditional cardiovascular risk factors and other variables, those working 11 to 12 hours per day had a 56 percent greater risk of coronary death, nonfatal myocardial infarction, or angina than those who worked normal hours, according to Marianna Virtanen, PhD, of the Finnish Institute of Occupational Health in Helsinki, and colleagues.

In an accompanying editorial, Gordon McInnes, MD, of the University of Glasgow, said that overtime-induced work stress might contribute to a substantial portion of cardiovascular disease.
“If the effect is truly causal, the importance is much greater than commonly recognized,” he wrote.

Although there is little evidence that easing stress reduces cardiovascular risk, “further research should examine whether interventions designed to reduce overtime work could alter the risk of cardiovascular disease.”

Overtime work has increased steadily in recent years, according to Virtanen and her colleagues, and there is mounting evidence that working extra hours is linked to poorer physical and mental health.

Read more: http://www.kevinmd.com/blog/2010/06/working-overtime-increase-coronary-artery-disease-risk.html