Long working hours as a risk factor for atrial fibrillation: A multi-cohort study
journal contributionposted on 2017-06-13, 09:55 authored by Mika Kivimaki, Solja T. Nyberg, G. David Batty, Ichiro Kawachi, Markus Jokela, Lars Alfredsson, Jakob B. Bjorner, Marianne Borritz, Hermann Burr, Nico Dragano, Eleonor I. Fransson, Katriina Heikkila, Anders Knutsson, Markku Koskenvuo, Meena Kumari, Ida E.H. Madsen, Martin L. Nielsen, Maria Nordin, Tuula Oksanen, Jan H. Pejtersen, Jaana Pentti, Reiner Rugulies, Paula Salo, Martin J. Shipley, Sakari Suominen, Tores Theorell, Jussi Vahtera, Peter J.M. Westerholm, Hugo Westerlund, Andrew Steptoe, Archana Singh-Manoux, Mark Hamer, Jane E. Ferrie, Marianna Virtanen, Adam G. Tabak
Aims Studies suggest that people who work long hours are at increased risk of stroke, but the association of long working hours with atrial fibrillation, the most common cardiac arrhythmia and a risk factor for stroke, is unknown. We examined the risk of atrial fibrillation in individuals working long hours (>55 per week) and those working standard 35-40 hours per week. Methods In this prospective multi-cohort study from the Individual-Participant-Data Meta-analysis in and results Working Populations (IPD-Work) Consortium, the study population was 85,494 working men and women (mean age 43.4 years) with no recorded atrial fibrillation. Working hours were assessed at study baseline (1991-2004). Mean follow-up for incident atrial fibrillation was 10 years and cases were defined using data on electrocardiograms, hospital records, drug reimbursement registers, and death certificates. We identified 1061 new cases of atrial fibrillation (10-year cumulative incidence 12.4 per 1000). After adjustment for age, sex and socioeconomic status, individuals working long hours had a 1.4-fold increased risk of atrial fibrillation compared to those working standard hours (hazard ratio=1.42, 95%CI=1.13-1.80, P=0.003). There was no significant heterogeneity between the cohortspecific effect estimates (I2=0%, P=0.66) and the finding remained after excluding participants with coronary heart disease or stroke at baseline or during the follow-up (N=2006, hazard ratio=1.36, 95%CI=1.05-1.76, P=0. 0180). Adjustment for potential confounding factors, such as obesity, risky alcohol use and high blood pressure, had little impact on this association. Conclusion Individuals who worked long hours were more likely to develop atrial fibrillation than those working standard hours.
IPD-Work consortium was supported by NordForsk, the EU New OSH ERA research programme, the Finnish Work Environment Fund, Finland, the Swedish Research Council for Working Life and Social Research, Sweden, Danish National Research Centre for the Working Environment, Denmark. Kivimaki was supported by NordForsk and the Medical Research Council (K013351).
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