The Effect of Sex Hormone Levels During the Menstrual Cycle on Capsaicin Evoked Cough
Overview
- Phase
- Not Applicable
- Intervention
- Not specified
- Conditions
- Asthma
- Sponsor
- McMaster University
- Enrollment
- 32
- Locations
- 1
- Primary Endpoint
- Emax
- Status
- Completed
- Last Updated
- 2 years ago
Overview
Brief Summary
The study aim is to investigate if changes in sex hormones during the menstrual cycle affects cough sensitivity in females and males with mild allergic asthma. Female subjects will be grouped according to natural cycle, or taking oral contraceptives. Male subjects will act as the control group.
Detailed Description
The study will have a total of 3 visits separated by at least 24 hours. Screening Period (Visits 1) - For All Subjects. Eligible subjects will be identified during the initial screening procedures with measures of spirometry, hyperresponsiveness to methacholine, complete history, physical examination, allergen skin test, and capsaicin cough challenge. For female subjects, this visit will occur during Day 1-5 (follicular phase) of the menstrual cycle. Subjects meeting the eligibility criteria will be randomized to Sequence A or Sequence B. Sequence A will require Visit 2 to occur during menstrual cycle days 1-5 (follicular phase) and Visit 3 to occur during menstrual cycle days 21 - 25 (luteal phase). Sequence B will require Visit 2 to occur during menstrual cycle days 21-25 (luteal phase) and Visit 3 to occur during menstrual cycle days 1 - 5 (follicular phase). During Visit 2 and 3 subjects will undergo measures of spirometry, hyperresponsiveness to methacholine, capsaicin cough challenge, allergen skin test, sputum and blood collection. Visit Windows Each visit must be separated by a minimum of 24 hours. Study visits can be performed in the morning or afternoon, however for each subject the timing should be consistent with Visit 1 at the same time of day ± 2 hours.
Investigators
Eligibility Criteria
Inclusion Criteria
- •Subjects must be aged between 18 to 35 years
- •Have a diagnosis of atopic asthma (based on at least one positive skin prick test and methacholine PC20 ≤16 mg/ml)
- •FEV1 ≥ 70% of predicted
- •Demonstrate a cough response to capsaicin with a minimum of 3 coughs during the screening capsaicin challenge
Exclusion Criteria
- •Subjects who are in a pollen season that affects their asthma
- •Subjects who report allergies to capsaicin or bronchoconstrict at the end of the full dose capsaicin cough challenge and require short acting bronchodilator therapy (assess after visit 1)
- •Subjects who do not display evidence of airway hyper-responsiveness (methacholine PC20\>16mg/ml) (assess after visit 1)
- •Symptoms of upper respiratory tract infection in the last 1 month which have not resolved.
- •Lower respiratory tract infection or pneumonia in the last 6 weeks.
- •Current smoker or ex-smoker with ≥10 pack year smoking history and abstinence of ≤6 months
- •Asthma exacerbation in the previous month requiring a start of inhaled or oral corticosteroids.
- •Any asthma medication with the exception of infrequent (less than twice weekly) short-acting β2-agonist.
- •Subjects who have changed asthma medication within the past 4 weeks prior to screening
- •A previous asthma exacerbation requiring Intensive Care Unit admission.
Outcomes
Primary Outcomes
Emax
Time Frame: One visit during day 1 to day 5 of the menstrual cycle, compared to one visit during day 21 to 25 of the menstrual cycle
The maximum number of capsaicin evoked coughs
Secondary Outcomes
- ED 50(One visit during day 1 to day 5 of the menstrual cycle, compared to one visit during day 21 to 25 of the menstrual cycle)
- Dose response Curve(One visit during day 1 to day 5 of the menstrual cycle, compared to one visit during day 21 to 25 of the menstrual cycle)
- C2 and C5(One visit during day 1 to day 5 of the menstrual cycle, compared to one visit during day 21 to 25 of the menstrual cycle)