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Combustion Derived Air Pollution and Vascular Function

Not Applicable
Completed
Conditions
Endothelial Dysfunction
Interventions
Procedure: Forearm Vascular Study
Procedure: Badimon Chamber
Registration Number
NCT00775099
Lead Sponsor
University of Edinburgh
Brief Summary

Air pollution is a major cause of cardiovascular morbidity and mortality. The components of air pollution responsible and the mechanisms through which they might mediate these harmful effects remain only partially understood. The link between cardiovascular disease and air pollution is strongest for fine particulate matter. Fine particulate matter (PM) is produced from the combustion of fossil fuels with the most significant threat thought to be posed by small particles less than 10µm (PM 10) which can be inhaled into the lungs. We propose to identify the precise component of diesel exhaust that mediates the adverse cardiovascular effects using a carbon particle generator, and a particle concentrator. The aim of this study proposal is to assess the vascular effects of different types and components of air pollution in healthy subjects. We intend to test the hypotheses that:

1. Combustion derived nanoparticulate causes an acute impairment of endothelial vasomotor and fibrinolytic function in healthy volunteers.

2. Exposure to combustion derived air pollution is associated with increased thrombus formation.

Detailed Description

Not available

Recruitment & Eligibility

Status
COMPLETED
Sex
All
Target Recruitment
16
Inclusion Criteria
  • Healthy volunteers
Exclusion Criteria
  • Current smokers
  • Significant occupational exposure to air pollution
  • History of lung disease
  • Women of child-bearing potential
  • Malignant arrhythmias
  • Renal or hepatic failure
  • Significant co-morbidity
  • Systolic blood pressure >190 or <100 mmHg
  • Previous history of blood dyscrasia
  • Unable to tolerate the supine position
  • Lack of informed consent
  • Blood donation within last 3 months

Study & Design

Study Type
INTERVENTIONAL
Study Design
CROSSOVER
Arm && Interventions
GroupInterventionDescription
Filtered Air ExposureForearm Vascular Study1 hour exposure to filtered air during intermittent exercise
Filtered Air ExposureBadimon Chamber1 hour exposure to filtered air during intermittent exercise
Diesel Exhaust ExposureForearm Vascular Study1 hour exposure to dilute diesel exhaust at a concentration of 300 µg/m3 during intermittent exercise
Diesel Exhaust ExposureBadimon Chamber1 hour exposure to dilute diesel exhaust at a concentration of 300 µg/m3 during intermittent exercise
Filtered Diesel ExposureForearm Vascular Study1 hour exposure to diesel exhaust with all particulates filtered out using teflon filter with intermittent exercise
Filtered Diesel ExposureBadimon Chamber1 hour exposure to diesel exhaust with all particulates filtered out using teflon filter with intermittent exercise
PALAS ExposureForearm Vascular Study1 hour exposure to pure carbon particles produced by PALAS generator during intermittent exercise
PALAS ExposureBadimon Chamber1 hour exposure to pure carbon particles produced by PALAS generator during intermittent exercise
Primary Outcome Measures
NameTimeMethod
Forearm blood flow measured by forearm venous occlusion plethysmography in response to infused vasodilators6-8 hours after exposure
Secondary Outcome Measures
NameTimeMethod
Heart rate and heart rate variability measured with 3 lead Holter electrographic monitorsDuring and for 24 hours after exposure
Ex-vivo thrombus formation assessed using the Badimon chamber6 hours after exposure
Blood pressureDuring and after exposure and during forearm study
Plasma t-PA and PAI concentrations following infusion of bradykininDuring forearm study
Arterial stiffness measured by radial artery tonometryBefore and after exposure
Plasma inflammatory markers IL-6, TNF-alpha, IL-1 and hsCRPBefore and after exposure
Platelet monocyte binding as measured by flow cytometryAfter the exposure

Trial Locations

Locations (1)

University of Edinburgh

🇬🇧

Edinburgh, United Kingdom

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