Aims To examine the association between overtime work and incident coronary heart disease (CHD) among middle-aged employees.
Methods and results Six thousand and fourteen British civil servants (4262 men and 1752 women), aged 39–61 years who were free from CHD and worked full time at baseline (1991–1994), were followed until 2002–2004, an average of 11 years. The outcome measure was incident fatal CHD, clinically verified incident non-fatal myocardial infarction (MI), or definite angina (a total of 369 events). Cox proportional hazard models adjusted for sociodemographic characteristics showed that 3–4 h overtime work per day was associated with 1.60-fold (95% CI 1.15–2.23) increased risk of incident CHD compared with employees with no overtime work. Adjustment for all 21 cardiovascular risk factors measured made little difference to these estimates (HR 1.56, 95% CI 1.11–2.19). This association was replicated in multivariate analysis with only fatal cardiovascular disease and incident non-fatal MI as the outcome (HR 1.67, 95% CI 1.02–2.76).
Conclusion Overtime work is related to increased risk of incident CHD independently of conventional risk factors. These findings suggest that overtime work adversely affects coronary health.
MariannaVirtanen, Jane E.Ferrie, ArchanaSingh-Manoux, Martin J.Shipley, JussiVahtera, Michael G.Marmot, MikaKivimäkiEur Heart J(2010)ehq124DOI: http://dx.doi.org/10.1093/eurheartj/ehq124First published online: 11 May 2010 ehq124