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NCT Number: NCT06509659

Methacholine Challenge Test (MCT) in Healthy Adults

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.

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Key information

Conditions

Hyperreactive Airway Disease Bronchial Diseases Bronchial Hyperreactivity Respiratory Tract Diseases

Age range

18 year–65 year

Sex eligibility

All sexes

Study type

Observational

Primary location

Thomas Ringbæk

Elsinore, 3140, Denmark

Location status: Recruiting

Location contact

Thomas J Ringbæk, MSci

CONTACT

[email protected]

21969087

About this study

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:

  • To determine the IOS response to MCT in healthy adults.
  • 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.

Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

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

Treatment and study plan

Methacholine Challenge Test

Diagnostic Test

MCT with IOS alone versus MCT IOS and FEV1 combined

Other names: FEV1 measurement

Primary outcomes

  1. Oscillometry; R5

    Time frame: baseline (carried out with FEV1 measurement)

    Resistance at 5 Hz; kPa/L/s with FEV1 measurement

  2. Oscillometry; R5

    Time frame: 1-10 days from baseline and carried out without FEV1 measurement

    Resistance at 5 Hz; kPa/L/s change from baseline

  3. Oscillometry; R20

    Time frame: baseline (carried out without FEV1 measurement)

    Resistance at 20 Hz; kPa/l/s with FEV1 measurement

  4. Oscillometry; R20

    Time frame: 1-10 days from baseline and carried out without FEV1 measurement

    Resistance at 20 Hz; kPa/L/s change from baseline

  5. Oscillometry; X5

    Time frame: baseline (carried out without FEV1 measurement)

    Reactance at 5 Hz; kPa/l/s with FEV1 measurement

  6. Oscillometry; X5

    Time frame: 1-10 days from baseline and carried out without FEV1 measurement

    Reactance at 5 Hz; kPa/L/s change from baseline

  7. Oscillometry; AX

    Time frame: baseline (carried out without FEV1 measurement)

    Area of reactance; kPa/L with FEV1 measurement

  8. Oscillometry; AX

    Time frame: 1-10 days from baseline and carried out without FEV1 measurement

    Area of reactance; kPa/L change from baseline

  9. Oscillometry; Fres

    Time frame: baseline (carried out without FEV1 measurement)

    Resonant frequency; Hz with FEV1 measurement

  10. Oscillometry; Fres

    Time frame: 1-10 days from baseline and carried out without FEV1 measurement

    Resonant frequency; Hz change from baseline

Study contacts

Contact information is provided by the study sponsor or research team.

Lars Frolund, MSci

CONTACT

[email protected]

Thomas Ringbæk, MSci

CONTACT

[email protected]

21969087

Sponsors and collaborators

Lead sponsor

Allergi- og Lungeklinikken, Elsinore

Network

Registry information

Official study title

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

Important dates

Study start
2024
Primary completion
2024
Study completion
2024
First posted
Jul 19, 2024
Registry last updated
Sep 19, 2024

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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