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Recruiting NCT06509659

Methacholine Challenge Test (MCT) in Healthy Adults

— Observational Hyperreactive Airway Disease

For patients and families

In plain language

An automatic summary of structured registry data. It is an orientation aid, not a substitute for the official protocol or a physician assessment.

What is being studied
The protocol lists: Methacholine Challenge Test.
Who it may be relevant to
Registry conditions: Hyperreactive Airway Disease. Basic parameters: 18 years — 65 years · All.
What needs checking
Age, condition and sex are only basic indicators. Prior treatment, laboratory values and other mandatory requirements appear in the eligibility criteria below.
Where it takes place
Denmark
Next step
Save the trial, show it to the treating physician, and confirm current recruitment with the study center. Costs, documents and travel →

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Official title

Methacholine Challenge Test (MCT) in Healthy Adults: Oscillometry Measured Alone Compared to Oscillometry and FEV1 During the Same Test

Overview

Knowledge of Methacholine Challenge Test (MCT) and impedance Oscillometry (IOS) is limited. Only three studies have included adult patients, and none of these with healthy controls. The three studies have combined IOS and spirometry in the same test, although it is not recommended to perform IOS after a test that requires deep breathing, e.g. FEV1 measurement. Deep breathing is considered to affect the impedance via reduced tone in the smooth muscle.

Detailed description

Asthma is a common chronic disease that is characterized by a history of variable respiratory symptoms and variable expiratory airflow limitation, and usually associated with airway hyperresponsiveness.

In general, FEV1 is used to test for airway hyperresponsiveness (AHR), and a 20% decrease after methacholine challenge test (MCT) is considered a positive test.

There is increasing recognition that the small airways are involved in 40-80% of patients with asthma, and the function of these airways is overlooked (the "silent zone") when measuring FEV1, which mainly reflects the function of the central airways.

Small airway dysfunction (SAD) can be assessed by IOS where pressure applied to the airways at a range of frequencies, and components of respiratory resistance and reactance are measured. Resistance at 5 Hz (R5) and 20 Hz (R20), respectively, represent total airway resistance and proximal airway resistance. The difference between these two values can be calculated (R5-R20). High R5-R20 and low reactance at 5 Hz (X5) indicate the presence of SAD.

Knowledge of MCT and IOS is limited. Only three studies have included adult patients, and none of these with healthy controls. These studies have combined IOS and spirometry in the same test, although it is not recommended to perform IOS after a test that requires deep breathing, e.g. FEV1 measurement. Deep breathing is considered to affect the impedance via reduced tone in the smooth muscle.

The investigators have the following objectives for these studies:

1. To determine the IOS response to MCT in healthy adults. 2. To investigate whether spirometry (FEV1) carried out in relation to MCT influences IOS by comparing the IOS response to MCT performed with and without spirometry in healthy adults.

Interventions

  • Diagnostic test Methacholine Challenge Test
    MCT with IOS alone versus MCT IOS and FEV1 combined

Primary outcome measures

  • Oscillometry; R5 [Time frame: baseline (carried out with FEV1 measurement)]
  • Oscillometry; R5 [Time frame: 1-10 days from baseline and carried out without FEV1 measurement]
  • Oscillometry; R20 [Time frame: baseline (carried out without FEV1 measurement)]
  • Oscillometry; R20 [Time frame: 1-10 days from baseline and carried out without FEV1 measurement]
  • Oscillometry; X5 [Time frame: baseline (carried out without FEV1 measurement)]
  • Oscillometry; X5 [Time frame: 1-10 days from baseline and carried out without FEV1 measurement]
  • Oscillometry; AX [Time frame: baseline (carried out without FEV1 measurement)]
  • Oscillometry; AX [Time frame: 1-10 days from baseline and carried out without FEV1 measurement]
  • Oscillometry; Fres [Time frame: baseline (carried out without FEV1 measurement)]
  • Oscillometry; Fres [Time frame: 1-10 days from baseline and carried out without FEV1 measurement]

Eligibility criteria

Inclusion criteria

  • Forced expiratory volume in the 1. second (FEV1) >80%
  • FEV1/FVC-ratio >0,7
  • FeNO <25 pbb
  • Oxygen saturation (SatO2) >95%
  • Negative methacholine Challenge Test = drop in FEV1 less than 20%

Exclusion criteria

  • Any lung disease
  • Lung symptoms
  • Medicine for lung disease
  • Tobacco smoking
  • Ex-smokers with more than 5 package years
  • BMI (body mass index) >40 kg/m2

Criteria are shown verbatim from the registry (in English). Final eligibility is always assessed by the study center.

Healthy volunteers: Yes

Study design

Observational model
Case-only

Study locations

Denmark · 1 center
  • Thomas Ringbæk — Elsinore

Publications

  • Coates AL, Wanger J, Cockcroft DW, Culver BH; Bronchoprovocation Testing Task Force: Kai-Hakon Carlsen; Diamant Z, Gauvreau G, Hall GL, Hallstrand TS, Horvath I, de Jongh FHC, Joos G, Kaminsky DA, Laube BL, Leuppi JD, Sterk PJ. ERS technical standard on bronchial challenge testing: general considerations and performance of methacholine challenge tests. Eur Respir J. 2017 May 1;49(5):1601526. doi: PMID 28461290
  • Cottini M, Lombardi C, Passalacqua G, Bagnasco D, Berti A, Comberiati P, Imeri G, Landi M, Heffler E. Small Airways: The "Silent Zone" of 2021 GINA Report? Front Med (Lausanne). 2022 May 23;9:884679. doi: 10.3389/fmed.2022.884679. eCollection 2022. PMID 35677830

Identifiers

NCT: NCT06509659 · Elsinore_Healthy

Primary sources (government registries)

View this study on ClinicalTrials.gov ↗