The relation of exposure to shift work with atherosclerosis and myocardial infarction in a general population

Objectives: We tested the hypothesis that working shifts is related to atherosclerosis and myocardial infarction. Background: The number of shift workers is continuously increasing. Shift work is discussed to be related with cardiovascular heart disease. Methods: A total of 25 10 Subjects recruited for the population-based Study of Health in Pomerania were tested, 698 of whom were former shift workers. A general population sample was examined to reach generalizibility and to produce results independent from the effects of the personal shift schedule and from the specific working conditions. Carotid ultrasound was performed to evaluate carotid intima-media thickness. We used multivariable analyses to estimate the coronary heart disease risk, adjusted for age, sex and atherosclerotic risk factors, stratified by exposure to shift work and its duration. Results: Atherosclerotic risk factors differed in part between shift workers and non-shift workers. Shift work was associated with atherosclerosis and myocardial infarction, depending on the duration of the exposure and the age of the participants. Multivariable Cox regression analysis identified shift work as a risk factor for myocardial infarction to be manifest at younger ages (adjusted hazard ratio 1.53, 95% CI 1.06-2.22). Conclusions: Exposure to shift work is a risk factor for atherosclerosis and myocardial infarction. Special prevention programs for shift workers should be provided. (C) 2008 Elsevier Ireland Ltd. All rights reserved.