title: Experimental exposure to diesel exhaust increases arterial stiffness in man.
abstract: BACKGROUND
  Exposure to air pollution is associated with increased cardiovascular morbidity, although the underlying mechanisms are unclear. Vascular dysfunction reduces arterial compliance and increases central arterial pressure and left ventricular after-load. We determined the effect of diesel exhaust exposure on arterial compliance using a validated non-invasive measure of arterial stiffness.
  
  
  METHODS
  In a double-blind randomized fashion, 12 healthy volunteers were exposed to diesel exhaust (approximately 350 mug/m3) or filtered air for one hour during moderate exercise. Arterial stiffness was measured using applanation tonometry at the radial artery for pulse wave analysis (PWA), as well as at the femoral and carotid arteries for pulse wave velocity (PWV). PWA was performed 10, 20 and 30 min, and carotid-femoral PWV 40 min, post-exposure. Augmentation pressure (AP), augmentation index (AIx) and time to wave reflection (Tr) were calculated.
  
  
  RESULTS
  Blood pressure, AP and AIx were generally low reflecting compliant arteries. In comparison to filtered air, diesel exhaust exposure induced an increase in AP of 2.5 mmHg (p = 0.02) and in AIx of 7.8% (p = 0.01), along with a 16 ms reduction in Tr (p = 0.03), 10 minutes post-exposure.
  
  
  CONCLUSIONS
  Acute exposure to diesel exhaust is associated with an immediate and transient increase in arterial stiffness. This may, in part, explain the increased risk for cardiovascular disease associated with air pollution exposure. If our findings are confirmed in larger cohorts of susceptible populations, this simple non-invasive method of assessing arterial stiffness may become a useful technique in measuring the impact of real world exposures to combustion derived-air pollution.
authors.affiliation: Department of Respiratory Medicine and Allergy, University Hospital, Umeå, Sweden. magnus.lundback@lung.umu.se.
authors.forename: Magnus
authors.initials: M
authors.lastname: Lundbäck
authors.forename: Nicholas L
authors.initials: NL
authors.lastname: Mills
authors.forename: Andrew
authors.initials: A
authors.lastname: Lucking
authors.forename: Stefan
authors.initials: S
authors.lastname: Barath
authors.forename: Ken
authors.initials: K
authors.lastname: Donaldson
authors.forename: David E
authors.initials: DE
authors.lastname: Newby
authors.forename: Thomas
authors.initials: T
authors.lastname: Sandström
authors.forename: Anders
authors.initials: A
authors.lastname: Blomberg