Long Working Hours and Risk of Recurrent Coronary Events

Xavier Trudel; Chantal Brisson; Denis Talbot; Mahée Gilbert-Ouimet; Alain Milot

doi:10.1016/j.jacc.2021.02.012

Long Working Hours and Risk of Recurrent Coronary Events

J Am Coll Cardiol. 2021 Apr 6;77(13):1616-1625. doi: 10.1016/j.jacc.2021.02.012.

Authors

Xavier Trudel¹, Chantal Brisson², Denis Talbot², Mahée Gilbert-Ouimet³, Alain Milot⁴

Affiliations

¹ Social and Preventive Medicine Department, Université Laval, Quebec City, Québec, Canada; CHU de Québec-Laval University Research Centre, Quebec City, Québec, Canada. Electronic address: xavier.trudel@crchudequebec.ulaval.ca.
² Social and Preventive Medicine Department, Université Laval, Quebec City, Québec, Canada; CHU de Québec-Laval University Research Centre, Quebec City, Québec, Canada.
³ CHU de Québec-Laval University Research Centre, Quebec City, Québec, Canada; Department of Health Sciences, Université du Québec à Rimouski, Lévis, Quebec City, Québec, Canada.
⁴ CHU de Québec-Laval University Research Centre, Quebec City, Québec, Canada; Medicine Department, Université Laval, Quebec City, Québec, Canada.

PMID: 33795035
DOI: 10.1016/j.jacc.2021.02.012

Abstract

Background: Evidence from prospective studies has suggested that long working hours are associated with incident coronary heart disease (CHD) events. However, no previous study has examined whether long working hours are associated with an increased risk of recurrent CHD events among patients returning to work after a first myocardial infarction (MI).

Objectives: The purpose of this study was to examine the effect of long working hours on the risk of recurrent CHD events.

Methods: This is a prospective cohort study of 967 men and women age 35 to 59 years who returned to work after a first MI. Patients were recruited from 30 hospitals across the province of Quebec, Canada. The mean follow-up duration was 5.9 years. Long working hours were assessed on average 6 weeks after their return to work. Incident CHD events (fatal or nonfatal MI and unstable angina) occurring during follow-up were determined using patients' medical files. Hazard ratios were estimated using Cox proportional hazard regression models. Splines and fractional polynomial regressions were used for flexible exposure and time modeling.

Results: Recurrent CHD events occurred among 205 patients. Participants working long hours (≥55 h/week) had a higher risk of recurrent CHD events after controlling for sociodemographics, lifestyle-related risk factors, clinical risk factors, work environment factors, and personality factors (hazard ratio vs. 35 to 40 h/week: 1.67; 95% confidence interval: 1.10 to 2.53). These results showed a linear risk increase after 40 h/week and a stronger effect after the first 4 years of follow-up and when long working hours are combined with job strain.

Conclusions: Among patients returning to work after a first MI, longer working hours per week is associated with an increased risk of recurrent CHD events. Secondary prevention interventions aiming to reduce the number of working hours among these patients may lower the risk of CHD recurrence.

Keywords: cohort study; epidemiology; risk factors; work stressors.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Adult
Coronary Disease / epidemiology*
Coronary Disease / etiology
Female
Humans
Male
Middle Aged
Myocardial Infarction
Occupational Stress / complications*
Prospective Studies
Quebec / epidemiology
Recurrence
Work Schedule Tolerance*
Workload*