Physiological Changes in Adults With Metabolic Syndrome Exposed to Ultrafine Air Particles (XCON)

November 5, 2013 updated by: David Diaz-Sanchez

Physiological Changes in Adults With Metabolic Syndrome Exposed to Concentrated Ultrafine Chapel Hill Air Particles

The purpose of this study is to examine the acute health effects of concentrated ambient ultrafine (UF) particulate matter (PM) exposure in patients with metabolic syndrome. Without lifestyle changes or medical intervention these patients are at considerable risk for developing diabetes and cardiovascular disease. Subjects (25-70) were exposed to both UF PM and filtered air for 2hr (at least 2 week interval), physiologic endpoints were measure pre-, post-, and 20hr post-exposure. Our hypothesis is that PM exposure in this population will result in changes in vascular and endothelial response as assessed by flow-mediated dilatation of the brachial artery and various heart rate variability and blood endpoints. This study and similar studies of susceptible populations are needed to provide the EPA with information regarding the health risks associated with ambient levels of UF PM.

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.
48

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

  • United States
    • North Carolina
      • Chapel Hill, North Carolina, United States, 27599
        • EPA Human Studies Facility

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

25 years to 70 years (ADULT, OLDER_ADULT)

Accepts Healthy Volunteers

No

Genders Eligible for Study

All

Description

Inclusion Criteria:

  • Age between 25-70 years old

  • Metabolic syndrome as defined by the participant having at least three of the following criteria:

    • Abdominal obesity: Men waist circumference >102 cm (>40 in) Women waist circumference >88 cm (>35 in)
    • Triglycerides: ≥150 mg/dL
    • HDL cholesterol: Men <40 mg/dL and Women <50 mg/dL
    • Blood pressure: ≥130/≥85 mmHg OR have a history of high blood pressure requiring medication
    • Fasting glucose: ≥100 mg/dL and ≤126 mg/dL
  • Normal resting electrocardiograph (ECG).

Exclusion Criteria:

  • Current smoker or smoking history within 3 months of study (defined as more than one pack of cigarettes in the past 3 months).
  • Oxygen saturation below 95% at the time of physical exam.
  • Blood pressure ≥160/≥100 mmHg
  • Fasting blood glucose >126 mg/dl
  • Hypersensitivity to nitroglycerin or other nitrates
  • Any chronic medical condition including active pulmonary disease, cardiovascular disease (coronary artery disease, heart failure, rhythm disturbances, etc.), neurological disease, liver disease, kidney disease, muscular disease, diabetes, other endocrine disease, hematologic/lymphatic disease, immune deficiency or autoimmune disease.
  • Medications specifically prohibited include nitrates or other vasodilators (exception here includes erectile dysfunction medications if the participant agrees to refrain for 96 hours prior to study), anti-arrhythmics, physician prescribed anti-inflammatory agents, physician prescribed antioxidants, insulin and other medications for the treatment of diabetes. Participants must refrain from all over-the-counter anti-inflammatory agents, including aspirin, ibuprofen, and naproxen, and anti-oxidants for a period of one week prior to exposure. Low dose aspirin and statin regimens are acceptable. Medications not specifically mentioned here may be reviewed by the investigators prior to a participant's inclusion in the study. Additionally, medication regimens must remain constant during the study.
  • Hepatitis B carriers
  • Skin diseases or sensitivity precluding the use of ECG electrodes
  • Active cancer, history of cancer within the last 5 years, untreated cancer. Potential participants may have a history of mild, treated skin cancer provided the condition does not interfere with ECG electrode placement.
  • No exposure will be conducted within 4 weeks of a respiratory tract infection.
  • History of serve migraines
  • Pregnant women or nursing mothers

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
  • Masking: SINGLE

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.
Active Comparator: Ultrafine Air Pollution Particulate Matter
<2.5 microns concentrated from outside ambient air
Other: Ultrafine Air Pollution Particulate Matter
Ultrafine (particle diameter less than 2.5 microns) Air Pollution Particulate Matter, concentrated from the ambient air outside of the Chapel Hill EPA Human Studies Facility
Other Names:
  • ultrafine particulate matter
  • concentrated ambient particulates (CAPS)
Sham Comparator: Filtered Air
Other: Filtered Air
Filtered Air
Other Names:
  • clean air

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
Measure Description
Time Frame
Changes in Vascular Function
Time Frame: change from baseline 0 hr after exposure, and change from baseline 20 hr after exposure. There will be at leat 2 weeks between the exposures
  1. Measurement of dilatation of the brachial artery (flow mediated and nitroglycerin mediated)
  2. Measurement of vasoconstrictor/vasodialtor, pro-coagulant, or pro-inflammatory mediators into systemic circulation (by ELISA of plasma)
  3. Measurement of changes in plasma levels of circulating microparticles and endothelial progenitor cells (as indicators of vascular injury or remodeling)
change from baseline 0 hr after exposure, and change from baseline 20 hr after exposure. There will be at leat 2 weeks between the exposures

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
Measure Description
Time Frame
Changes in heart rate variability
Time Frame: change from baseline 0 hr after exposure, and change from baseline 20 hr after exposure. There will be at leat 2 weeks between the exposures
10 minute electrocardiogram recording (measure by Holter ECG) in which the subject has been resting for 20 minutes prior. Collected on a Mortara H12+ 12-Lead ECG Recorder (Mortara Instrument, Inc., Milwaukee, WI). The digitally recorded ECGs were sampled at 180 Hz and all data were stored on flash cards before processing.
change from baseline 0 hr after exposure, and change from baseline 20 hr after exposure. There will be at leat 2 weeks between the exposures

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.
David Diaz-Sanchez

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.
Environmental Protection Agency (EPA)

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: Robert B Devlin, PhD, US EPA
  • Principal Investigator: Candice B Smith, PhD, US EPA

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.
December 1, 2004

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, 2011

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.
October 1, 2013

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).
November 14, 2011

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.
November 17, 2011

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.
November 22, 2011

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.
November 7, 2013

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.
November 5, 2013

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.
November 1, 2013

More Information

Terms related to this study

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.
  • XCON
  • 04-1677 (Other Identifier: UNC IRB)

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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