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Cardiopulmonary Responses to Exposure to Ozone and Diesel Exhaust (DEPOZ)

10 juin 2013 mis à jour par: Michael Madden, Environmental Protection Agency (EPA)

Cardiopulmonary Responses to Exposure to Ozone and Diesel Exhaust With Moderate Exercise in Healthy Adults

The US EPA Clean Air Multiyear research program is moving toward a multi-pollutant approach to the assessment of air pollution in response to recommendations by the NRC 2004 and the BOSC in 2005. Such an approach better reflects the complexity of real-world air pollution problems and parallels evolving scientific and regulatory considerations. Ozone (O3) and diesel exhaust (DE) generally are major and important components of ambient air pollution. This proposed study will address the agency's goals by investigating the cardiopulmonary health effects in healthy human subjects co-exposed to O3 and DE. The findings derived from these exposures will provide NCEA findings for risk assessments of O3 and DE, as well as the Office of Air and Radiation (includes OTAQ and OAQPS) with information relevant to possible modulation of PM-induced health effects and responses by a gaseous co-pollutant for potential standard setting. Additionally the findings will address the fundamental driving principle of the Clean Air Research strategy related to reduction of health due to air pollutant exposures.

Aperçu de l'étude

Statut

Complété

Intervention / Traitement

Description détaillée

Numerous epidemiological studies have demonstrated an association between acute and chronic exposure to air pollution and various adverse cardiopulmonary effects including mortality, respiratory tract infections, exacerbation of asthma symptoms, chronic bronchitis, ischemic heart disease, and stroke [1] and other health effects. Understanding the components responsible for these effects is difficult because ambient air pollution is a complex mixture of gases and particulate matter (PM). In this complex mixture of ambient air pollution, ozone (O3) and diesel exhaust (DE) are generally major and important components. Controlled exposure of volunteers to either pollutant have resulted in biological effects such as lung physiological changes. However it is not known if co-exposure to both pollutants, similar to polluted ambient air, can induce additive or synergistic effects. Additionally it is also uncertain if exposure to DE, or DE with O3, can alter a subsequent exposure to O3 similar to multiple day exposures that the general population receives. This study proposes to examine whether co-exposures to O3 and DE can induce additive or synergistic effects, and whether a previous DE exposure alters a response upon subsequent exposure to O3. The potential effects of O3 on cardiac electrophysiology are also not clear.

Approximately 15 healthy non-smoking volunteers between the ages of 18 and 55 will be exposed in a controlled manner to O3 (approximately mean concentration of 0.3 ppm over the 2 hr exposure period), or diesel exhaust (DE; ~300 µg/m3), or a combined O3 and DE exposure while undergoing moderate intermittent exercise at the EPA Human Studies Facility. A clean air exposure will serve as a control. Primary endpoints for evaluating health effects and surrogate responses are changes in lung function and heart rate variability. In addition, other cardiopulmonary and vascular biological endpoints will be measured, as well as markers of exposure and genetic markers of susceptibility.

Type d'étude

Interventionnel

Inscription (Réel)

15

Phase

  • N'est pas applicable

Contacts et emplacements

Cette section fournit les coordonnées de ceux qui mènent l'étude et des informations sur le lieu où cette étude est menée.

Lieux d'étude

    • North Carolina
      • Chapel Hill, North Carolina, États-Unis, 27514
        • US EPA Human Studies Facility

Critères de participation

Les chercheurs recherchent des personnes qui correspondent à une certaine description, appelée critères d'éligibilité. Certains exemples de ces critères sont l'état de santé général d'une personne ou des traitements antérieurs.

Critère d'éligibilité

Âges éligibles pour étudier

18 ans à 55 ans (Adulte)

Accepte les volontaires sains

Oui

Sexes éligibles pour l'étude

Tout

La description

Inclusion Criteria:

  • Healthy men and women between 18 and 55 years of age
  • Physical conditioning allowing intermittent, moderate exercise for 2 hours
  • Normal lung function:

    1. FVC > 75 % of that predicted for gender, ethnicity, age and height.
    2. FEV1 > 75 % of that predicted for gender, ethnicity, age and height.
    3. FEV1/FVC ratio > 75 % of predicted values.
  • Oxygen saturation > 96 %.

Exclusion Criteria:

  • A history of acute and chronic cardiovascular disease, chronic respiratory disease, diabetes, rheumatologic diseases, immunodeficiency state, and acute respiratory illness within 4 weeks.
  • Subjects who are asthmatic or have a history of asthma.
  • Allergic to chemical vapors or gases.
  • Any allergic symptoms during the time of participation in the study
  • Female subjects who are currently pregnant, attempting to become pregnant, or breastfeeding
  • Subjects unwilling or unable to stop taking vitamin C or E or medications which may impact the results of the ozone challenge (such as, systemic steroids and beta blockers) at least 2 weeks prior to the study and for the duration of the study. Medications not specifically mentioned here may be reviewed by the investigators prior to a subject's inclusion in the study.
  • Current and past smokers within 1 year.
  • Uncontrolled hypertension (> 150 systolic, > 90 diastolic).
  • Subjects who do not understand or speak English
  • Subjects unable to perform the moderately active exercise required for the study.
  • Subjects with a history of skin allergies to adhesives used in securing heart rate monitor electrodes.
  • Unspecified diseases or conditions, which in the judgment of the investigator might influence the responses to the exposures, will be a basis for exclusion.
  • Subjects unwilling to stop taking over-the-counter pain medications such as aspirin, Advil, Aleve or other non-steroidal anti-inflammatory medications ("NSAIDS") for 48 hr prior to the exposures and post-exposure visits.
  • Subjects with a marked baseline prolongation of QT/QTc interval (e.g., repeated demonstration of a QTc interval >450 milliseconds (ms))

Plan d'étude

Cette section fournit des détails sur le plan d'étude, y compris la façon dont l'étude est conçue et ce que l'étude mesure.

Comment l'étude est-elle conçue ?

Détails de conception

  • Objectif principal: Diagnostique
  • Répartition: Randomisé
  • Modèle interventionnel: Affectation factorielle
  • Masquage: Double

Armes et Interventions

Groupe de participants / Bras
Intervention / Traitement
Comparateur placebo: Filtered air exposure
2 hr exposure to clean, filtered air with intermittent exercise
Exposure to 300 ppb ozone with intermittent exercise about 20 hr after exposure to each arm (ie, either air, ozone, diesel exhaust, or ozone combined with diesel exhaust)
Autres noms:
  • cas # 10028-15-6
  • trioxygen
Expérimental: Ozone
2 hr exposure to 300 ppb ozone with intermittent exercise
Exposure to 300 ppb ozone with intermittent exercise about 20 hr after exposure to each arm (ie, either air, ozone, diesel exhaust, or ozone combined with diesel exhaust)
Autres noms:
  • cas # 10028-15-6
  • trioxygen
Expérimental: Diesel Exhaust, No ozone
2 hr exposure to whole diesel exhaust (300 ug/m3; gases + particles) with intermittent exercise; no ozone
Exposure to 300 ppb ozone with intermittent exercise about 20 hr after exposure to each arm (ie, either air, ozone, diesel exhaust, or ozone combined with diesel exhaust)
Autres noms:
  • cas # 10028-15-6
  • trioxygen
Expérimental: Ozone + Diesel Exhaust
2 hr exposure to a combination of 300 ppb ozone an 300 ug/m3 whole diesel exhaust with intermittent exercise
Exposure to 300 ppb ozone with intermittent exercise about 20 hr after exposure to each arm (ie, either air, ozone, diesel exhaust, or ozone combined with diesel exhaust)
Autres noms:
  • cas # 10028-15-6
  • trioxygen

Que mesure l'étude ?

Principaux critères de jugement

Mesure des résultats
Description de la mesure
Délai
Lung Function Decrement
Délai: Immediately post to 24 hr post exposure
Lung function decrements are typically expressed as changes in FEV1 and FVC. Measurements are made pre-exposure (defined as baseline, immediately post exposure, 1-4 hr post exposure, and 24 hr post exposure (follow up).
Immediately post to 24 hr post exposure

Mesures de résultats secondaires

Mesure des résultats
Délai
Heart rate variability
Délai: immediately post to 24 hr post exposure
immediately post to 24 hr post exposure

Autres mesures de résultats

Mesure des résultats
Description de la mesure
Délai
plasma cytokine levels
Délai: immediately post to 24 hr post exposur
Inflammation markers such as interleukin 8
immediately post to 24 hr post exposur

Collaborateurs et enquêteurs

C'est ici que vous trouverez les personnes et les organisations impliquées dans cette étude.

Les enquêteurs

  • Chercheur principal: Michael Madden, PhD, Environmental Protection Agency (EPA)

Publications et liens utiles

La personne responsable de la saisie des informations sur l'étude fournit volontairement ces publications. Il peut s'agir de tout ce qui concerne l'étude.

Dates d'enregistrement des études

Ces dates suivent la progression des dossiers d'étude et des soumissions de résultats sommaires à ClinicalTrials.gov. Les dossiers d'étude et les résultats rapportés sont examinés par la Bibliothèque nationale de médecine (NLM) pour s'assurer qu'ils répondent à des normes de contrôle de qualité spécifiques avant d'être publiés sur le site Web public.

Dates principales de l'étude

Début de l'étude

1 août 2010

Achèvement primaire (Réel)

1 avril 2012

Achèvement de l'étude (Réel)

1 janvier 2013

Dates d'inscription aux études

Première soumission

7 juin 2013

Première soumission répondant aux critères de contrôle qualité

10 juin 2013

Première publication (Estimation)

11 juin 2013

Mises à jour des dossiers d'étude

Dernière mise à jour publiée (Estimation)

11 juin 2013

Dernière mise à jour soumise répondant aux critères de contrôle qualité

10 juin 2013

Dernière vérification

1 juin 2013

Plus d'information

Termes liés à cette étude

Ces informations ont été extraites directement du site Web clinicaltrials.gov sans aucune modification. Si vous avez des demandes de modification, de suppression ou de mise à jour des détails de votre étude, veuillez contacter register@clinicaltrials.gov. Dès qu'un changement est mis en œuvre sur clinicaltrials.gov, il sera également mis à jour automatiquement sur notre site Web .

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