ClinicalTrials.gg
CompletedNCT00143637Updated Mar 27, 2008

Dose Response Relations for Health Effects Caused by Office Dust

A Phase 1/2 interventional study of Office dust and clean air in Discomfort Symptoms and Changed Lung Function, sponsored by University of Aarhus. Completed at 1 site in Denmark. Open to participants aged 18 Years to 64 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2008-03-27.

Sponsored by University of Aarhus · Phase 1/2, Interventional, and Prevention

Phase
Phase 1/2
Study type
Interventional
Enrollment
24
Allocation
Non-randomized
Ages
18 Years to 64 Years
Sex
All
01

Study summary

The study is focused at the dose response relation for office dust and such office dust spiked with components from fungi known from damp buildings.

The first aim of this study is to investigate if dust causes objective changes such as changes of lung function, nasal geometry, inflammatory indicators in tears and nasal lavage, tear film stability and cells at exposure levels relevant to indoor air. The controlled exposure variable is air concentration of office dust spiked with Glucan to simulate a worse case scenario.

Aim 1: Confirm or support the causality between objective effects and exposures to dust spiked with Glucan with focus on inflammatory responses. This is done by negation of the hypothesis that no significant effects are found for the variables in question.

Aim 2 is to estimate the thresholds and slopes of the DR relation for effect measures which show effects of exposures. At best the study will supply for each variable a zero response to clean air and three non-zero responses to dust. Thresholds and slopes are estimated graphically by linear regression or by an accumulated response model.

Aim 3 is a confirmation that atopic persons and histamine sensitive persons in nasal provocation tests have different responses in the effect measures showing significant effects of exposures to dust spiked with Glucan. Risk group status is therefore included in the analyses of the main variables as explaining variable.

Potential additional aim 4: Chemical and biological characterization of the office dust used in the study.

Aim 4 is an investigation of dose response relations for explorative measures, which in previous investigations have showed indications of a dose response relation. For these no a priory hypotheses exists and the analyses must be arranged ad hoc. The explaining variables are exposure and risk group status.

One challenge in investigations of unspecific effects caused by mixed exposures is that few specific objective effects measures are available and subjective measures have to be introduced. Therefore there is a need for developments of new objective measures of health effects of air pollution. Some of these are related to new biomarkers of respiratory effects in a bio-sample taken as condensed exhaled breath.

Aim 5: Developments of new objective measures of health effects of air pollution. After the experiment it will be investigated by logistic regression if a sensitivity index can be established.

Read the detailed description

The basic procedure is an exposure experiment in which human subjects are exposed to controlled variations of dust spiked with Glucan. Their responses are monitored before, after minutes and hours of exposure and later the same evening.

Two groups of subjects are selected in a pre-investigation using strict selection and exclusion criteria. The two groups are atopic persons and responders to Histamine in a RSM nasal provocation test.

The groups are exposed under controlled conditions in a climate chamber at IMA to office dust spiked with Glucan (same procedure and amount as in DAMOS) at clean air level (less than 20 micro-g/m3 (TSP) and at 150, 300 and 700 micro-g/m3 (TSP). In the pre-investigation and during the exposure sessions a number of personal characteristics are measured or registered to be used in the statistical analyses as explaining variables for the responses of the subjects.

The dust exposure will be characterized both though its size distribution and gravimetrically using up-to-date analytical instruments. To optimise the exposures several pilot studies are made. Only effects measures, which previously have shown clear indications of responses to dust exposures, are included in the study.

The timetable includes pre-investigations, two repetitions of the exposure design (run 1 and 2), analyses of the bio-samples, statistical analyses, and reporting.

The study includes a main study and several additional work-packages, which will be activated when funding become available.

02

Conditions studied

  • Discomfort Symptoms
  • Changed Lung Function

Browse trials for

Keywords

  • Office dust
  • Glucan
  • dose-response
  • lung function
  • peak expiratory flow
  • inflammation
  • perception
03

In context

Inflammation

3,512 studies on the registry are indexed under Inflammation; 640 are open to participants now.

This study's enrollment of 24 is below the median of 50 across 2,491 interventional studies indexed under Inflammation.

Browse Inflammation studies →

Lead sponsor

University of Aarhus is the lead sponsor of 1,299 studies on the registry; 189 are open to participants now.

Counted across the registry records on this site, refreshed daily.

04

Who can participate

Ages eligible
18 Years to 64 Years
Sexes eligible
All
Accepts healthy volunteers
Yes

Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.

Inclusion criteria

  • All in local area
  • Nasal histamine responsive
  • Grass allergic

Exclusion criteria

Exclusion Criteria:

  • Pregnancy
  • House dust allergy
  • Hyper-responding air ways, Disease
05

Study design

Phase
Phase 1 / Phase 2
Primary purpose
Prevention
Allocation
Non-randomized
Intervention model
Crossover assignment
Masking
Triple (Participant, Investigator, Outcomes assessor)
Enrollment
24 participants (actual)

Study arms

  • Experimental
    2

    Office dust with added glucan

    Other: Office dust

  • Experimental
    1

    Clean air exposures in climate chamber

    Other: clean air

Interventions

  • OtherOffice dust

    airborne office dust spiked with glucan

    Also known as: Glucan

  • Otherclean air

    Clean air

06

What researchers measure

Primary outcomes

  1. Lung Inflammation

    Time frame: during exposures

Secondary outcomes

  1. Lung function

    Time frame: during exposures

  2. FEV

    Time frame: during exposures

  3. FVC

    Time frame: during exposures

  4. Acoustic rhinometry

    Time frame: during exposures

  5. cytokine profile

    Time frame: during exposures

  6. Peak expiratory flow

    Time frame: during exposures

  7. inflammation and sensory symptoms

    Time frame: during exposures

07

Study locations

1 site
  • The Air Pollution Unit, Department of Environmental and Occupational Medicine, Institute of Public Health, The University of Aarhus.
    Aarhus, DK-8000, Denmark
08

Timeline

Tracking since Sep 25, 2026
Not marked actual or estimatedDates not marked actual or estimated

The record gives a start of May 2005, a primary completion of Nov 2006 and a completion of Nov 2006. It does not say whether these dates are actual or estimated.

How these figures are worked out, and which studies are left out of them.

Registered
Sep 1, 2005
First posted
Sep 2, 2005
Start
May 2005
Primary completionActual
Nov 2006
CompletionActual
Nov 2006
Last update
Mar 27, 2008
What these dates mean
Start.
When the first participant enrolled; while estimated, when the study expects to open to recruitment.
Primary completion.
When the last participant was examined or treated to collect data for the study's main question, its primary outcome. A study that stopped early gives the date its data collection stopped.
Completion.
When the last participant's last visit took place, for every outcome, secondary ones and side effects included: the end of the study. Often later than primary completion, sometimes the same day.
Actual and Est.
Actual means the registry says the date has happened. Est. (estimated) is a date the sponsor plans or expects. It can still move, and the sponsor is expected to change it to actual once it has passed.
No changes since tracking began. The registry record was last updated on Mar 27, 2008, before this site started recording changes on Sep 25, 2026. Its history is on ClinicalTrials.gov ↗
09

Registry details

Key details

Study ID
NCT00143637
Collaborators
The Swedish Research Council for Environment, Agricultural Sciences and Spatial Planning (FORMAS), Service Branchens Arbejdsgiverforening i Danmark
First posted
Sep 2, 2005
Start date
May 2005
Primary completion
Nov 2006
Completion
Nov 2006
Last update
Mar 27, 2008

Study contacts

Lars Mølhave, DMSc, Ph.D.
principal investigator · The Air Pollution Unit, Department of Environmental and Occupational Medicine, Institute of Public Health, The University of Aarhus.

Oversight

Data monitoring committee
No
View the source record on ClinicalTrials.gov ↗

Not currently enrolling

This study is completed, as verified in Mar 2008. You cannot join it, but the record below documents what was studied.

Follow this study

Get an email when the registry record changes — status, dates, results — or when someone posts here.

Sign in to follow

Discussion

Questions and observations about this study, from anyone following it. Not medical advice, and not a channel to the study team — their contact details are on the registry record.

Sign in to join the discussion. Reading takes no account; posting does. You choose a display name, and a pseudonym is the default.

Nothing here yet. If you are running this trial, taking part in it, or weighing whether to, this is the place to say so.

Start the discussion