title: Are hypertensive women at additional risk of ischaemic heart disease from physically demanding work?
abstract: The combination of hypertension and high physical activity at work may increase blood pressure considerably and increase the risk of atherosclerosis and thereby ischaemic heart disease (IHD), but only a few studies in men, and none among women, have examined this topic.
  
  
  
  This was a prospective cohort study.
  
  
  
  In 1993, 12,093 female nurses from the Danish Nurse Cohort Study, aged 45-64 years answered a baseline questionnaire on physical activity at work, history of hypertension, a selection of known risk factors for IHD and occupational factors. Information on incident IHD from baseline to 2008 was retrieved by individual linkage to the National Register of Hospital Discharges.
  
  
  
  In a fully adjusted Cox model, hypertensive nurses with high physical activity at work had nearly three times higher risk of IHD (hazard ratio (HR) 2.87 (95% confidence interval (CI) 2.12-3.87)) compared to normotensive nurses with moderate physical activity at work. Significant additive interaction between physical activity at work and hypertension was found measured by the relative excess risk due to additive interaction (RERI) (1.20 (95% CI 0.26-2.14), and in an additive hazards model. Hypertensive nurses with high physical activity at work had 60 additional cases of IHD per 10,000 person years compared to normotensive nurses with moderate physical activity at work (60.0 (95% CI 38.1-81.9; p < 0.001)), of which more than half was explained by additive interaction (40.7 (95% CI 11.7-69.7; p = 0.006)). No multiplicative interaction (p = 0.249) was found.
  
  
  
  This study among Danish nurses indicated that hypertensive women may be at particular high risk of IHD from physically demanding work.
authors.affiliation: Department of Sports Science and Clinical Biomechanics, University of Southern Denmark, Denmark Research Centre for Prevention and Health, Centre for Health, Rigshospitalet-Glostrup, Denmark karen.allesoee@regionh.dk.
authors.forename: Karen
authors.initials: K
authors.lastname: Allesøe
authors.affiliation: Department of Sports Science and Clinical Biomechanics, University of Southern Denmark, Denmark.
authors.forename: Karen
authors.initials: K
authors.lastname: Søgaard
authors.affiliation: Research Centre for Prevention and Health, Centre for Health, Rigshospitalet-Glostrup, Denmark Department of Public Health, University of Copenhagen, Denmark.
authors.forename: Mette
authors.initials: M
authors.lastname: Aadahl
authors.affiliation: Department of Sports Science and Clinical Biomechanics, University of Southern Denmark, Denmark Dalla Lana School of Public Health, University of Toronto, Canada.
authors.forename: Eleanor
authors.initials: E
authors.lastname: Boyle
authors.affiliation: Department of Sports Science and Clinical Biomechanics, University of Southern Denmark, Denmark National Research Centre for the Working Environment, Denmark.
authors.forename: Andreas
authors.initials: A
authors.lastname: Holtermann
mesh_terms: D002423:Cause of Death / Q000639:trends; D003718:Denmark / Q000453:epidemiology; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D006973:Hypertension / Q000150:complications* / Q000503:physiopathology; D015994:Incidence; D008875:Middle Aged; D009043:Motor Activity; D017202:Myocardial Ischemia / Q000453:epidemiology / Q000209:etiology*; D016273:Occupational Exposure / Q000009:adverse effects*; D016272:Occupational Health; D011446:Prospective Studies; D016387:Women's Health; D016526:Workload
keywords: Heart disease; hypertension; occupational health; physical activity; prospective study; women