title: Exposure to wood smoke increases arterial stiffness and decreases heart rate variability in humans.
abstract: BACKGROUND
  Emissions from biomass combustion are a major source of indoor and outdoor air pollution, and are estimated to cause millions of premature deaths worldwide annually. Whilst adverse respiratory health effects of biomass exposure are well established, less is known about its effects on the cardiovascular system. In this study we assessed the effect of exposure to wood smoke on heart rate, blood pressure, central arterial stiffness and heart rate variability in otherwise healthy persons.
  
  
  METHODS
  Fourteen healthy non-smoking subjects participated in a randomized, double-blind crossover study. Subjects were exposed to dilute wood smoke (mean particle concentration of 314±38 μg/m3) or filtered air for three hours during intermittent exercise. Heart rate, blood pressure, central arterial stiffness and heart rate variability were measured at baseline and for one hour post-exposure.
  
  
  RESULTS
  Central arterial stiffness, measured as augmentation index, augmentation pressure and pulse wave velocity, was higher after wood smoke exposure as compared to filtered air (p < 0.01 for all), and heart rate was increased (p < 0.01) although there was no effect on blood pressure. Heart rate variability (SDNN, RMSSD and pNN50; p = 0.003, p < 0.001 and p < 0.001 respectively) was decreased one hour following exposure to wood smoke compared to filtered air.
  
  
  CONCLUSIONS
  Acute exposure to wood smoke as a model of exposure to biomass combustion is associated with an immediate increase in central arterial stiffness and a simultaneous reduction in heart rate variability. As biomass is used for cooking and heating by a large fraction of the global population and is currently advocated as a sustainable alternative energy source, further studies are required to establish its likely impact on cardiovascular disease.
  
  
  BACKGROUND
  ClinicalTrials.gov, NCT01488500.
authors.forename: Jon
authors.initials: J
authors.lastname: Unosson
authors.forename: Anders
authors.initials: A
authors.lastname: Blomberg
authors.forename: Thomas
authors.initials: T
authors.lastname: Sandström
authors.forename: Ala
authors.initials: A
authors.lastname: Muala
authors.forename: Christoffer
authors.initials: C
authors.lastname: Boman
authors.forename: Robin
authors.initials: R
authors.lastname: Nyström
authors.forename: Roger
authors.initials: R
authors.lastname: Westerholm
authors.forename: Nicholas L
authors.initials: NL
authors.lastname: Mills
authors.forename: David E
authors.initials: DE
authors.lastname: Newby
authors.forename: Jeremy P
authors.initials: JP
authors.lastname: Langrish
authors.forename: Jenny A
authors.initials: JA
authors.lastname: Bosson
mesh_terms: D000328:Adult; D001794:Blood Pressure / Q000187:drug effects; D018592:Cross-Over Studies; D004311:Double-Blind Method; D005080:Exercise Test; D005260:Female; D006339:Heart Rate / Q000187:drug effects*; D006801:Humans; D019570:Inhalation Exposure / Q000009:adverse effects; D008297:Male; D063177:Pulse Wave Analysis; D018570:Risk Assessment; D012906:Smoke / Q000009:adverse effects*; D013997:Time Factors; D059289:Vascular Stiffness / Q000187:drug effects*; D014934:Wood / Q000009:adverse effects*; D055815:Young Adult
chemical_list: D012906:Smoke