Does Sildenafil Increase Exercise Performance in Air Pollution?

Study Overview
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Brief Summary
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The purpose of this study is to examine if the ingestion of a standard dose of sildenafil enhances the athletic performance of competitive athletes when exercising in a high pollutant environment verses a low air pollutant environment.

Detailed Description
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This study will evaluate effects of sildenafil on exercise performance while breathing high levels of emission exhaust ultrafine and fine particulate matter. Exercise performance will be measured by work accumulation (total kJ) during a 6-min maximal effort cycle ergometer ride (CER) done immediately after 30 min cycling at 75% of 6 min mean watts determined from familiarization trial. Peak oxygen consumption, cardiac output, pulmonary artery pressure, diffusion capacity(DLco), and SaO2 will be determined for each trial. Blood and urine will be analyzed for sildenafil using LC/MS.

Official Title
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Decreased Pulmonary Artery Pressure by Oral Sildenafil Injection During Exercise in Air Pollution Increases Exercise Performance.

Conditions
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Pulmonary Hypertension, Pulmonary Artery Pressure, Exercise Performance, Air Pollution

Intervention / Treatment
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* Drug: sildenafil
* Other: placebo


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: non-asthmatic asthmatic active participants in endurance sports. Exclusion Criteria: history of high blood pressure history of heart disease pulmonary arterial hypertension pulmonary emboli diagnosis of moderate to severe asthma (FEV1 <75% predicted) pregnant or lactating

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 30 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: Parallel Assignment
Masking: Triple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: 1<br>Subjects will exercise in a high air pollutant environment after ingesting a standard dose of sildenafil. | Drug: sildenafil<br>* sildenafil 50 mg ingested orally 1 hour prior to exercise testing<br>* Other names: Viagra;|
| Active Comparator: 2<br>Subjects will exercise in a low pollutant environment after ingesting a standard dose of sildenafil. | Drug: sildenafil<br>* sildenafil 50 mg ingested orally 1 hour prior to exercise testing<br>* Other names: Viagra;|
| Placebo Comparator: 3<br>Subjects will exercise in a high pollutant environment after ingesting a placebo. | Other: placebo<br>* matching placebo for sildenafil 50 mg to be ingested orally 1 hour prior to exercise testing.<br>* Other names: sugar pill;|
| Placebo Comparator: 4<br>Subjects will exercise in a low pollutant environment after ingesting a placebo. | Other: placebo<br>* matching placebo for sildenafil 50 mg to be ingested orally 1 hour prior to exercise testing.<br>* Other names: sugar pill;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| That a decrease in exercise performance subsequent to emissions particle inhalation will be blunted by oral ingestion of 50 mg sildenafil prior to a 6-min maximal accumulation test (total kJ)on a cycle ergometer. |  | Cycle ergometer testing will be done one hour after administration of sildenafil or matching placebo. | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| That the decreased VO2 peak and decreased exercise performance from emissions inhalation will be the result of pulmonary hypertension causing decreased stroke volume. |  | Pulmonary artery pressure will be measured before and immediately post exercise. | 
| That plasma and urine sildenafil and metabolites will be measurable by liquid chromatography mass spectrometry (LC/MS) 6 h post ingestion. |  | Blood and urine samples will be collected at 1, 3, 1nd 6 hours post exercise testing. | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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phosphodiesterase, sildenafil, pulmonary hypertension, exercise performance, air pollution