title: Is aerobic workload positively related to ambulatory blood pressure? A cross-sectional field study among cleaners.
abstract: OBJECTIVE
  Cardiovascular disease is prevalent among workers with high levels of occupational physical activity. The increased risk may be due to a high relative aerobic workload, possibly leading to increased blood pressure. However, studies investigating the relation between relative aerobic workload and ambulatory blood pressure (ABP) are lacking. The aim was to explore the relationship between objectively measured relative aerobic workload and ABP.
  
  
  METHODS
  A total of 116 cleaners aged 18-65 years were included after informed consent was obtained. A portable device (Spacelabs 90217) was mounted for 24-h measurements of ABP, and an Actiheart was mounted for 24-h heart rate measurements to calculate relative aerobic workload as percentage of relative heart rate reserve. A repeated-measure multi-adjusted mixed model was applied for analysis.
  
  
  RESULTS
  A fully adjusted mixed model of measurements throughout the day showed significant positive relations (p < 0.001): a 1% increase in mean relative aerobic workload was associated with an increase of 0.42 ± 0.05 mmHg (95% CI 0.32-0.52 mmHg) in systolic ABP and 0.30 ± 0.04 mmHg (95% CI 0.22-0.38 mmHg) in diastolic ABP. Correlations between relative aerobic workload and ABP were significant.
  
  
  CONCLUSIONS
  Because workers may have an elevated relative aerobic workload for several hours each working day, this relationship may elucidate a mechanism behind the increased risk for cardiovascular disease among workers exposed to high levels of occupational physical activity.
authors.affiliation: The National Research Centre for the Working Environment, Lersø Parkallé 105, 2100, Copenhagen Ø, Denmark. mkl@nrcwe.dk.|Department of Nutrition, Exercise and Sports, Copenhagen Centre for Team Sport and Health, University of Copenhagen, Nørre Allé 51, 2200, Copenhagen N, Denmark. mkl@nrcwe.dk.
authors.forename: Mette
authors.initials: M
authors.lastname: Korshøj
authors.affiliation: Department of Public Health, Ghent University, De Pintelaan 185, 9000, Ghent, Belgium.
authors.forename: Els
authors.initials: E
authors.lastname: Clays
authors.affiliation: The National Research Centre for the Working Environment, Lersø Parkallé 105, 2100, Copenhagen Ø, Denmark.
authors.forename: Mark
authors.initials: M
authors.lastname: Lidegaard
authors.affiliation: The National Research Centre for the Working Environment, Lersø Parkallé 105, 2100, Copenhagen Ø, Denmark.
authors.forename: Jørgen H
authors.initials: JH
authors.lastname: Skotte
authors.affiliation: The National Research Centre for the Working Environment, Lersø Parkallé 105, 2100, Copenhagen Ø, Denmark.|Institute of Sports Science and Clinical Biomechanics, University of Southern Denmark, Campusvej 55, 5230, Odense M, Denmark.
authors.forename: Andreas
authors.initials: A
authors.lastname: Holtermann
authors.affiliation: Department of Nutrition, Exercise and Sports, Copenhagen Centre for Team Sport and Health, University of Copenhagen, Nørre Allé 51, 2200, Copenhagen N, Denmark.|Sport and Health Sciences, College of Life and Environmental Sciences, University of Exeter, St. Luke's Campus, Exeter, UK.
authors.forename: Peter
authors.initials: P
authors.lastname: Krustrup
authors.affiliation: Institute of Sports Science and Clinical Biomechanics, University of Southern Denmark, Campusvej 55, 5230, Odense M, Denmark.
authors.forename: Karen
authors.initials: K
authors.lastname: Søgaard
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001794:Blood Pressure / Q000502:physiology*; D018660:Blood Pressure Monitoring, Ambulatory / Q000379:methods; D003430:Cross-Sectional Studies; D015444:Exercise / Q000502:physiology*; D005260:Female; D006339:Heart Rate / Q000502:physiology; D006801:Humans; D006973:Hypertension / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D016526:Workload; D055815:Young Adult
keywords: Cardiovascular disease; Cardiovascular risk factor; Diurnal; Heart rate reserve; Objective measurements; Physical workload