Heart Disease
Conditions
Keywords
Air pollution, Diesel exhaust, Endothelial function, Vascular function, Particle trap, Thrombosis, effects, inhalation
Brief summary
The purpose of this study is to determine whether a retrofit particle trap can reduce the adverse vascular responses to diesel exhaust inhalation
Detailed description
18 subjects healthy male volunteers will be recruited at Umeå University. In a randomised, double blind 3 way crossover trial, subjects will be exposed to filtered air, diesel exhaust (300mcg/m3) or filtered diesel exhaust for 1 hour during intermittent exercise. 2 hours following the exposure, thrombogenicity will be assessed using the Badimon chamber - an ex-vivo model of thrombosis formed under constant flow conditions. Forearm blood flow in response to infused intra-brachial vasodilators will be measured using venous occlusion plethysmography 6 hours after the exposure. Arterial stiffness will be measured using peripheral arterial applanation tonometry in the hour post-exposure. Blood samples will be collected at timepoints over the 24 hours after exposure.
Interventions
Forearm venous occlusion plethysmography with intra-arterial infusion of Acetylcholine (5-20mcg/min), bradykinin (30-300mcg/min), sodium nitroprusside (2-8mcg/min) and Verapamil (2-10 mcg/min) into non-dominant brachial artery
Sponsors
Umeå University
University of Edinburgh
Study design
Allocation
RANDOMIZED
Intervention model
CROSSOVER
Primary purpose
BASIC_SCIENCE
Masking
QUADRUPLE (Subject, Caregiver, Investigator, Outcomes Assessor)
Eligibility
Sex/Gender
MALE
Age
18 Years to 35 Years
Healthy volunteers
Yes
Inclusion criteria
* Healthy male volunteers
Exclusion criteria
* Intercurrent illness * Smoking * Significant occupational exposure to air pollution * Regular medication usage
Design outcomes
Primary
| Measure | Time frame |
|---|---|
| Forearm blood flow in response to infused intra-arterial vasodilators | 6 hours post-exposure |
Secondary
| Measure | Time frame |
|---|---|
| Arterial stiffness measured by applanation tonometry | In the 1 hour following exposure |
| Thrombogenicity measured using the Badimon chamber - an ex-vivo model of thrombosis under conditions of continuous flow | 2 hours after the exposure |
| Exhaled nitric oxide - a marker of pulmonary inflammation | 1 hour & 6 hours after exposure |
| Endogenous fibrinolytic capacity - measured as net release of t-PA in response to infused bradykinin | 6 hours after exposure |
| Biochemical markers of systemic inflammation | Baseline, 2, 6 & 24 hours |
Countries
Sweden
Outcome results
None listed