Diesel Exhaust Inhalation, Systemic Nitric Oxide Inhibition and Cardiac Output (DISCO)

December 15, 2011 updated by: University of Edinburgh
Exposure to combustion-derived fine particulate air pollution is associated with cardiovascular mortality and morbidity. In previous studies, exposure to diesel exhaust (a major constituent of urban particulate air pollution) has been shown to impair two important functions of the vascular endothelium: vascular vasomotor function and endogenous fibrinolysis. Our subsequent studies suggest this impairment of vascular function is mediated by a reduction in nitric oxide bioavailability. In this study we aim to investigate the cardiovascular responses to systemic nitric oxide synthase inhibition following exposure to dilute diesel exhaust.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Completed

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Actual)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
14

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • Sweden
      • Umeå, Sweden
        • University Hospital Umeå

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

18 years and older (Adult, Older Adult)

Accepts Healthy Volunteers

Yes

Genders Eligible for Study

All

Description

Inclusion Criteria:

  • Healthy volunteers
  • Non smokers
  • No regular medication (except oral contraceptive)
  • No recent respiratory tract infection (within 6 weeks)

Exclusion Criteria:

  • History of asthma or respiratory disease
  • Smoking history
  • Pregnancy (positive urinary pregnancy test)

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Basic Science
  • Allocation: Randomized
  • Interventional Model: Crossover Assignment
  • Masking: Triple

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Experimental: Diesel exhaust exposure
1 hour exposure to dilute diesel exhaust ~ 300 mcg/m3 - during intermittent exercise
Drug: Intravenous infusion of L-NMMA and Nor-epinephrine
Intravenous infusion of 3mg/kg L-NMMA (L-NG-monomethyl arginine; NO synthase inhibitor) and nor-epinephrine at 50 ng/kg/min. Each infusion to run over 15 mins and separated by 45 min to allow return to baseline. Drugs infused in a randomised order. During the study, blood pressure will be measured invasively using an intra-arterial radial artery cannula, central arterial stiffness measured using peripheral arterial tonometry and cardiac output using thoracic bioimpedance.
Other Names:
  • L-NMMA: Clinalfa Basic, Bachem, Germany
Experimental: Air exposure
1 hour exposure to filtered air during intermittent exercise
Drug: Intravenous infusion of L-NMMA and Nor-epinephrine
Intravenous infusion of 3mg/kg L-NMMA (L-NG-monomethyl arginine; NO synthase inhibitor) and nor-epinephrine at 50 ng/kg/min. Each infusion to run over 15 mins and separated by 45 min to allow return to baseline. Drugs infused in a randomised order. During the study, blood pressure will be measured invasively using an intra-arterial radial artery cannula, central arterial stiffness measured using peripheral arterial tonometry and cardiac output using thoracic bioimpedance.
Other Names:
  • L-NMMA: Clinalfa Basic, Bachem, Germany

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Time Frame
Blood pressure response to NO inhibition
Time Frame: Blood pressure will be measured continuously through the vascular study using intra-arterial monitoring
Blood pressure will be measured continuously through the vascular study using intra-arterial monitoring

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Time Frame
Heart rate response to systemic nitric oxide inhibition
Time Frame: Heart rate will be measured continuously throughout the study period using continous electrocardiography
Heart rate will be measured continuously throughout the study period using continous electrocardiography
Central arterial stiffness following NO inhibition
Time Frame: Measured at baseline, and every 5 minutes during the 2-hour vascular study
Measured at baseline, and every 5 minutes during the 2-hour vascular study
Cardiac output during NO inhibition
Time Frame: Measured at baseline, and every 5 minutes during the 2-hour vascular study
Measured at baseline, and every 5 minutes during the 2-hour vascular study
Plasma nitrite (NO) concentrations
Time Frame: Measured at baseline, and every 15 minutes during the 2-hour vascular study
Measured at baseline, and every 15 minutes during the 2-hour vascular study
Platelet activation and platelet-monocyte binding
Time Frame: Measured at baseline, and every 30 minutes during the 2-hour vascular study
Measured at baseline, and every 30 minutes during the 2-hour vascular study
Heart rate variability
Time Frame: Heart rate will be measured continuously throughout the study period using continous electrocardiography, and HRV subsequently determined for the whole study period and the 2-hour vascular study separately
Heart rate will be measured continuously throughout the study period using continous electrocardiography, and HRV subsequently determined for the whole study period and the 2-hour vascular study separately

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
University of Edinburgh

Collaborators

Collaborators

An organization other than the sponsor that provides support for a clinical study. This support may include activities related to funding, design, implementation, data analysis, or reporting.
Umeå University
NHS Lothian

Investigators

Investigators

A researcher involved in a clinical study. Related terms include site principal investigator, site sub-investigator, study chair, study director, and study principal investigator.
  • Principal Investigator: Jeremy P Langrish, MB BCh MRCP, University of Edinburgh

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
March 1, 2010

Primary Completion (Actual)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
June 1, 2010

Study Completion (Actual)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
June 1, 2010

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
January 28, 2010

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
February 1, 2010

First Posted (Estimate)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
February 2, 2010

Study Record Updates

Last Update Posted (Estimate)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
December 16, 2011

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
December 15, 2011

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
April 1, 2011

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • DISCO

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