The Effect of a Retrofit Particle Trap on the Vascular Effects of Diesel Exhaust Inhalation

Study Overview
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Brief Summary
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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
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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.

Official Title
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The Effect of a Retrofit Particle Trap on the Vascular Effects of Diesel Exhaust Inhalation

Conditions
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Heart Disease

Intervention / Treatment
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* Procedure: Forearm Venous Occlusion Plethysmography


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Healthy male volunteers Exclusion Criteria: Intercurrent illness Smoking Significant occupational exposure to air pollution Regular medication usage

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 35 Years

Sexes Eligible for Study
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Male

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Basic Science
Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: Quadruple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: 1<br>1 hour exposure to filtered air | Procedure: Forearm Venous Occlusion Plethysmography<br>* 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<br>|
| Experimental: 2<br>1 hour exposure to diesel exhaust (300mcg/m3) | Procedure: Forearm Venous Occlusion Plethysmography<br>* 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<br>|
| Experimental: 3<br>1 hour exposure to filtered diesel exhaust | Procedure: Forearm Venous Occlusion Plethysmography<br>* 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<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Forearm blood flow in response to infused intra-arterial vasodilators |  | 6 hours post-exposure | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | 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 | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Air pollution, Diesel exhaust, Endothelial function, Vascular function, Particle trap, Thrombosis, effects, inhalation