ORIGINAL ARTICLE

A 12 year prospective study of circulatory disease among Danish shift workers

F Tüchsen, H Hannerz, H Burr

National Institute of Occupational Health, Copenhagen, Denmark

Correspondence to:
Dr F Tüchsen
National Institute of Occupational Health, Lersø Parkallé 105, DK-4000 Copenhagen Ø, Denmark; ft{at}ami.dk

Background: Previous studies of the risk of heart disease after shift work reached different estimates and review authors disagree about the validity of some of the studies. A cross sectional study showed that shift workers had a higher prevalence of nearly every unfavourable work environment factor investigated. Conflicts at work and low decision latitude were more frequent among shift workers, and all-day walking or standing work and part-time jobs were more often found among female shift workers.

Objectives: To estimate the risk of circulatory disease in a prospective follow up of a representative sample of gainfully employed Danes, considering known or suspected confounding factors.

Methods: A cohort of 5517 people who were gainfully employed in 1990 were followed up for all hospital treatments due to circulatory diseases (390–458, ICD-8; I00–I99, ICD-10) from 1991 to 2002 inclusive. A log linear Poisson regression model was applied to control confounding factors and calculate the relative risk for 927 men and women working nights, evenings, or other non-day shifts compared to 4579 day workers.

Results: Non-day workers compared to day workers had a relative risk (RR) for all circulatory diseases of 1.31 (95% CI 1.06–1.63). Without control for BMI and smoking, the RR estimate was 1.33 (95% CI 1.07–1.65). For a subgroup of workers with at least three years’ seniority, the RR was 1.40 (95% CI 1.09–1.81). The population based aetiological fraction of shift work was estimated to 5%.

Conclusion: This study adds to a growing body of evidence suggesting that shift work carries an excess risk of circulatory diseases.

Abbreviations: BMI, body mass index; CHD, coronary heart disease; IHD, ischaemic heart disease; RR, relative risk; SRR, standardised rate ratio

Keywords: follow-up study; heart diseases; hospitalisation; night work; non-day work

CiteULike    Complore    Connotea    Del.icio.us    Digg    Reddit    Technorati    What's this?

This article has been cited by other articles:

• Little, M P, Tawn, E J, Tzoulaki, I, Wakeford, R, Hildebrandt, G, Tapio, S, Elliott, P (2009). Comments: The non-cancer mortality experience of male workers at British Nuclear Fuels plc, 1946-2005. Int J Epidemiol 38: 1159-1164 [Full Text]  
• De Bacquer, D, Van Risseghem, M, Clays, E, Kittel, F, De Backer, G, Braeckman, L (2009). Rotating shift work and the metabolic syndrome: a prospective study. Int J Epidemiol 38: 848-854 [Abstract] [Full Text]  
• Brown, D. L., Feskanich, D., Sanchez, B. N., Rexrode, K. M., Schernhammer, E. S., Lisabeth, L. D. (2009). Rotating Night Shift Work and the Risk of Ischemic Stroke. Am J Epidemiol 169: 1370-1377 [Abstract] [Full Text]  
• Scheer, F. A. J. L., Hilton, M. F., Mantzoros, C. S., Shea, S. A. (2009). From the Cover: Adverse metabolic and cardiovascular consequences of circadian misalignment. Proc. Natl. Acad. Sci. USA 106: 4453-4458 [Abstract] [Full Text]  
• Wang, C.-Y., Wen, M.-S., Wang, H.-W., Hsieh, I-C., Li, Y., Liu, P.-Y., Lin, F.-C., Liao, J. K. (2008). Increased Vascular Senescence and Impaired Endothelial Progenitor Cell Function Mediated by Mutation of Circadian Gene Per2. Circulation 118: 2166-2173 [Abstract] [Full Text]  
• Tuchsen, F, Christensen, K B, Lund, T, Feveile, H (2008). A 15-year prospective study of shift work and disability pension. Occup. Environ. Med. 65: 283-285 [Abstract] [Full Text]  
• Palmer, K. (2006). Work in brief. Occup. Environ. Med. 63: 437-437 [Full Text]  
• Tuchsen, F, Hannerz, H, Roepstorff, C, Krause, N (2006). Stroke among male professional drivers in Denmark, 1994-2003. Occup. Environ. Med. 63: 456-460 [Abstract] [Full Text]