Working Long Hours May Predict Risk of Heart Disease
Information on working hours should be added to traditional risk factors to improve risk prediction
TUESDAY, April 5 (HealthDay News) -- Working long hours may increase the risk of coronary heart disease (CHD), and information on working hours can improve CHD prediction in a low-risk, employed population, according to a study published in the April 5 issue of the Annals of Internal Medicine.
Mika Kivimäki, Ph.D., from University College London, and colleagues assessed whether adding information on long working hours to traditional risk factors improves prediction of CHD. A cohort of 1,095 adults aged 39 to 62 years without CHD at baseline had their working hours and Framingham risk score measured at baseline. Medical screenings every five years, hospital data, and registry linkage that was provided were used to evaluate the risk of coronary death and nonfatal myocardial infarction during an average follow-up period of 12.3 years.
The researchers identified 192 cases of incident CHD. After adjusting for Framingham risk scores, a 1.67 fold increased risk of CHD was seen in participants working 11 hours or more per day compared to those working seven to eight hours per day. A net reclassification improvement of 4.7 percent was observed with the addition of working hours to the Framingham risk score due to improved identification of individuals who developed CHD.
"We demonstrated that long working hours predict the incident hard end point of CHD and contribute to CHD risk prediction over and above the Framingham risk score," the authors write.