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Experimental Exposure to Air Pollutants and Sympathetic Nerve Activity in Human Subjects (Particles)

The recruitment status of this study is unknown. The completion date has passed and the status has not been verified in more than two years.
Verified July 2013 by Prof. Dr. Jens Jordan, Hannover Medical School.
Recruitment status was:  Recruiting
Sponsor:
ClinicalTrials.gov Identifier:
NCT01914783
First Posted: August 2, 2013
Last Update Posted: August 2, 2013
The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details.
Collaborator:
Fraunhofer-Institute of Toxicology and Experimental Medicine
Information provided by (Responsible Party):
Prof. Dr. Jens Jordan, Hannover Medical School
July 30, 2013
August 2, 2013
August 2, 2013
July 2013
December 2015   (Final data collection date for primary outcome measure)
Muscle sympathetic nerve activity (MSNA) [ Time Frame: 2.5 hours after exposure to clean air, to ultrafine particles, or to a combination of ultrafine particles and ozone ]
Change of sympathetic vasoconstrictor nerve activity directed to skeletal muscle expressed as sympathetic bursts per minute. The primary hypothesis of the study is that in healthy elderly subjects experimental exposure to air pollutants increases sympathetic nervous system activity compared with sham (clean air) exposure.
Same as current
No Changes Posted
  • MSNA burst incidence [ Time Frame: 2.5 hours after exposure to clean air, to ultrafine particles, or to a combination of ultrafine particles and ozone ]
    Change of MSNA expressed as bursts/100 heart beats.
  • total MSNA [ Time Frame: 2.5 hours after exposure to clean air, to ultrafine particles, or to a combination of ultrafine particles and ozone ]
    Change of MSNA expressed as burst area/min.
Same as current
  • Blood pressure [ Time Frame: 2.5 hours after exposure to clean air, to ultrafine particles, or to a combination of ultrafine particles and ozone ]
    Change of blood pressure in mmHg.
  • Heart rate [ Time Frame: 2.5 hours after exposure to clean air, to ultrafine particles, or to a combination of ultrafine particles and ozone ]
    Change of heart rate in beat per minute.
  • Cardiac output [ Time Frame: 2.5 hours after exposure to clean air, to ultrafine particles, or to a combination of ultrafine particles and ozone ]
    Change of cardiac output in l/min.
  • Total peripheral resistance [ Time Frame: 2.5 hours after exposure to clean air, to ultrafine particles, or to a combination of ultrafine particles and ozone ]
    Change in total peripheral resistance expressed as dyn*s/cm^5.
  • Heart rate variability. [ Time Frame: 2.5 hours after exposure to clean air, to ultrafine particles, or to a combination of ultrafine particles and ozone ]
    Change in heart rate variability parameters in the time and frequency domain.
  • Plasma norepinephrine concentration [ Time Frame: 2.5 hours after exposure to clean air, to ultrafine particles, or to a combination of ultrafine particles and ozone ]
    Change of plasma norepinephrine in ng/l.
  • Plasma renin concentration [ Time Frame: 2.5 hours after exposure to clean air, to ultrafine particles, or to a combination of ultrafine particles and ozone ]
    Change of plasma renin concentration in
  • Baroreflex sensitivity [ Time Frame: 2.5 hours after exposure to clean air, to ultrafine particles, or to a combination of ultrafine particles and ozone ]
    Change in baroreflex sensitivity expressed as ms/mmHg.
  • Inflammation parameters [ Time Frame: 3.5 hours after exposure to clean air, to ultrafine particles, or to a combination of ultrafine particles and ozone ]
    Change of the percentage of neutrophils in induced sputum.
  • Oxidative stress parameters [ Time Frame: 2.5 hours after exposure to clean air, to ultrafine particles, or to a combination of ultrafine particles and ozone ]
    Change of plasma malondialdehyde(MDA)concentration.
  • Correlation between inflammation, oxidative stress and cardiovascular regulation [ Time Frame: 2.5 hours after exposure to clean air, to ultrafine particles, or to a combination of ultrafine particles and ozone ]
    Correlation coefficients between changes in parameters for inflammation and oxidative stress with changes in cardiovascular parameters.
  • Forced expiratory volume in one second (FEV1) [ Time Frame: 2.5 hours after exposure to clean air, to ultrafine particles, or to a combination of ultrafine particles and ozone ]
    Change in FEV1 in l
  • Forced vital capacity (FVC) [ Time Frame: 2.5 hours after exposure to clean air, to ultrafine particles, or to a combination of ultrafine particles and ozone ]
    Change in FVC in l.
  • Percentage of neutrophils in peripheral blood [ Time Frame: 2.5 hours after exposure to clean air, to ultrafine particles, or to a combination of ultrafine particles and ozone ]
    Change of percentage of neutrophils in peripheral blood.
Same as current
 
Experimental Exposure to Air Pollutants and Sympathetic Nerve Activity in Human Subjects
Experimental Exposure to Air Pollutants and Sympathetic Nerve Activity in Human Subjects
The primary hypothesis of the study is that in healthy elderly subjects experimental exposure to air pollutants increases sympathetic nervous system activity compared with sham (clean air) exposure. The secondary hypothesis of the study is that combined experimental exposure to air pollutants (particles + ozone) increases sympathetic nervous system activity to a greater extent than does the exposure to particles alone.
In a randomized, double-blind, and cross-over fashion, the participants will be exposed to clean air, ultrafine particles, or ultrafine particles and ozone in an exposure chamber. The investigators will determine blood pressure, heart rate, respiration as well as cardiac output and directly record sympathetic vasomotor tone using the microneurography technique. To elucidate the underlying mechanisms through which particles and ozone affect the autonomic nervous system, the investigators will assess the local and systemic inflammatory response as well as the changes in neurotrophic factors in sputum and blood. In addition, the activation of inflammatory cells in sputum and blood will be analyzed at different points in time after exposures. Changes in sympathetic activity will be correlated with the degree of airway inflammation and oxidative stress assessed in induced sputum and blood. This study will provide important insight in the mechanisms through which air pollution, particularly ultrafine particle exposure, increases cardiovascular risk in human subjects and generate a human model for mechanistic and therapeutic studies.
Interventional
Not Provided
Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: Triple (Participant, Investigator, Outcomes Assessor)
Primary Purpose: Supportive Care
Cardiovascular Morbidity
  • Other: ultrafine particles
    exposure to ultrafine particles
  • Other: ultrafine particles and ozone
    exposure to ultrafine particles and ozone
  • Other: clean air
    Exposure to clean air.
  • Experimental: ultrafine particles
    Subjects will be exposed to ultrafine particles for three hours in an exposure chamber. During that time participants will perform intermittent bicycle ergometer training. Training intensity is adjusted individually to increase ventilation to 20 l/min/m². During exposure, heart rate will be monitored continuously via ECG. Blood pressure will be measured every 15 minutes. Ultrafine elemental carbon black particles are generated using a commercially available electric spark generator. Particle number, mass, and size distribution will be monitored during exposure.
    Intervention: Other: ultrafine particles
  • Active Comparator: ultrafine particles and ozone
    Subjects will be exposed to ultrafine particles for three hours in an exposure chamber. During that time participants will perform intermittent bicycle ergometer training. Training intensity is adjusted individually to increase ventilation to 20 l/min/m². During exposure, heart rate will be monitored continuously via ECG. Blood pressure will be measured every 15 minutes. Ultrafine elemental carbon black particles are generated using a commercially available electric spark generator. Particle number, mass, and size distribution will be monitored during exposure.Ozone is generated from medical oxygen in order to maintain a concentration of 250 ppb.
    Intervention: Other: ultrafine particles and ozone
  • Placebo Comparator: clean air
    Subjects will be exposed to clean air for three hours in an exposure chamber controlled for temperature, humidity, and gas/particle composition. During that time they will perform intermittent bicycle ergometer training for 15 minutes alternating with 15 minutes rest. Training intensity is adjusted individually to increase ventilation to 20 l/min/m². During exposure, heart rate will be monitored continuously via ECG. The blood pressure will be measured in time intervals of 15 minutes.
    Intervention: Other: clean air
Tank J, Biller H, Heusser K, Holz O, Diedrich A, Framke T, Koch A, Grosshennig A, Koch W, Krug N, Jordan J, Hohlfeld JM. Effect of acute ozone induced airway inflammation on human sympathetic nerve traffic: a randomized, placebo controlled, crossover study. PLoS One. 2011 Apr 8;6(4):e18737. doi: 10.1371/journal.pone.0018737.

*   Includes publications given by the data provider as well as publications identified by ClinicalTrials.gov Identifier (NCT Number) in Medline.
 
Unknown status
30
December 2015
December 2015   (Final data collection date for primary outcome measure)

Inclusion Criteria:

  • Elderly man or postmenopausal woman older than 50 years of age.
  • Signed written informed consent.

Exclusion Criteria:

  • Smoker.
  • Cardiovascular and/or pulmonary disease.
  • Medication with relevant impact on autonomic system function, e. g. norepinephrine reuptake inhibitors. Stable medication with slight to moderate autonomic effects is tolerable.
  • Subject is the investigator or any sub-investigator, research assistant, pharmacist, study coordinator, other staff or relative thereof directly involved in the conduct of the protocol.
  • Mental condition rendering the subject unable to understand the nature, scope, and possible consequences of the study.
  • Subject unlikely to comply with protocol, e. g. uncooperative attitude or unlikelihood of completing the study.
  • Known hypersensitivity to ozone.
  • History of drug or alcohol abuse. Particles Study - Protocol version: October 19, 2012 14
  • Blood donation of more than 500 mL during the previous 3 months.
Sexes Eligible for Study: All
50 Years and older   (Adult, Senior)
Yes
Contact information is only displayed when the study is recruiting subjects
Germany
 
 
NCT01914783
MHH-Particles EK-6142
No
Not Provided
Not Provided
Prof. Dr. Jens Jordan, Hannover Medical School
Hannover Medical School
Fraunhofer-Institute of Toxicology and Experimental Medicine
Not Provided
Hannover Medical School
July 2013

ICMJE     Data element required by the International Committee of Medical Journal Editors and the World Health Organization ICTRP