Pulmonary Rehabilitation for Uncontrolled Asthma Associated With Elevated BMI

Aim to evaluate the impact of a pulmonary rehabilitation (rehab) programme tailored and delivered to overweight and obese patients with difficult asthma on:

1. Asthma related quality of life (primary outcome) and asthma control (secondary outcome)
2. Treatment burden and healthcare usage (secondary outcomes)
3. Physical activity level, exercise tolerance, lung function and inflammation (secondary outcome)
4. Anxiety and depression (secondary outcome)

Eligible individuals will be identified through Difficult Asthma Clinics or ward admissions. Those wishing to participate will receive an information sheet and be invited to provide written informed consent prior to commencing the study.

Baseline Visit

Measurements taken at the baseline visit will include:

Demographics - age, gender, smoking history (current, ex, none, years since stopped, pack years), age at asthma diagnosis, duration of asthma, atopy, co-morbidities (allergic/perennial rhinitis, nasal polyps, nasal surgery, eczema, gastro-oesophageal reflux disease (GORD), diabetes, hypertension, cardiac disease, osteopenia/osteoporosis etc), medications (inhaled/nebulised short acting beta2-agonists (SABA), inhaled and oral corticosteroids (OCS) etc), healthcare usage (oral corticosteroid boosts, unscheduled general practice (GP) or accident and emergency (A+E) attendances, hospital and intensive care unit (ICU) admissions in preceding year), weight, height and body mass index (BMI).

Questionnaires - Medical Research Council (MRC) dyspnoea scale, Asthma Control Questionnaire (ACQ6), Asthma Quality of Life Questionnaire (AQLQ), and Hospital Anxiety and Depression Scale (HAD).

Inflammatory - Blood eosinophils, Fraction of exhaled nitric oxide (FENO).

Lung Function - peak expiratory flow (PEF) (best of 3), Spirometry (pre- and post-bronchodilator).

Exercise tolerance - 6 minute walk test (6MWT) (practice test and repeat test), Modified Borg Dyspnoea Scale, pulse oximetry.

Physical Activity - actigraphy

Participants will be provided with a Personalized Asthma Management Plan, and Symptoms Diary that includes SABA use and other healthcare usage (OCS) boosts, unscheduled GP or A+E attendances, hospital and ICU admissions); inhaler technique will be corrected if necessary.

Participants will be randomized 1:1 to Group A and Group B. Group A will enter the 8 week pulmonary rehabilitation arm of the study immediately while Group B will enter the 8 week usual care arm. Group A will return for Visit 2 and Group B for Visit 1(2) at 8 weeks.

Measurements taken at Visits 1(2), 2. and 3 will include:

Demographics - medications (inhaled/nebulised short acting beta2-agonists (SABA), inhaled and oral corticosteroids etc), healthcare usage (OCS) boosts, unscheduled GP or A+E attendances, hospital and ICU admissions since last visit), weight, height, and BMI.

Questionnaires - MRC dyspnoea scale, Asthma Control Questionnaire (ACQ6), Asthma Quality of Life Questionnaire (AQLQ), and Hospital Anxiety and Depression Scale (HAD).

Inflammatory - Blood eosinophils, Fraction of exhaled nitric oxide (FENO).

Lung Function - PEF (best of 3), Spirometry (pre- and post-bronchodilator).

Exercise tolerance - 6 minute walk test, Modified Borg Dyspnoea Scale, pulse oximetry.

Physical Activity - actigraphy

After Visit 2, Group A will discontinue pulmonary rehabilitation; Group A will return for Visit 3 (48 weeks). Group B will enter the 8 week pulmonary rehabilitation arm and return for Visit 2 at 16 weeks; Group B will return for Visit 3 (56 weeks). Visits will be postponed by 4 weeks in the event of exacerbation or respiratory infection. Throughout the study period changes to asthma medications will be allowed as clinically indicated.

Pulmonary rehabilitation arm

The pulmonary rehabilitation course will be provided on a rolling basis and for each individual will be of 8 weeks duration including once weekly, 1.5 hour hospital sessions and encouragement to perform twice weekly home exercise sessions. Hospital sessions will include 1 hour of supervised exercise and 30 minutes education. Hospital sessions will run in Glasgow Royal Infirmary every Thursday morning with education (11:15-11:45) and exercise (12:00-13:00). Sessions will run with minimum 6 participants and aiming for 12-16.

Exercise Component: This will include a combination of aerobic, resistance and flexibility training. Participants will be screened prior to commencing exercise to confirm stability of asthma. Pre-exercise administration of bronchodilators (participant's own salbutamol inhaler) will occur and there will a gradual warm-up with stretches for 7 to 8 minutes. The prescribed training intensity will be defined by the exercise capacity during baseline 6MWT with progressive increase in repetitions. Nebulised salbutamol will be available in the venue. Individuals will then rotate through the following exercises:

12 leg extensions alternating right/left (R/L) +/- weights 12 arm weights (R/L together) 12 step ups Bike 12 Sit to stands 12 pole raises 12 knee lifts (alternating R/L) Walk

Educational Component: This will include the following topics:

What is asthma - and relation to physical activity Medications in asthma Recognizing warning signs, self management and personalized asthma action plans Inhaler technique and PEF recording Co-morbidities and asthma Dysfunctional breathing and breathing control exercises Anxiety management Relaxation Chest clearance Health promotion - smoking cessation, healthy eating etc Benefits of exercise and maintenance

On completion of the formal pulmonary rehabilitation course, participants will be encouraged to continue regular exercise sessions by accessing community based "Vitality Classes".

Usual care arm

During this 8 week period, individuals will be asked not to alter their physical activity level from baseline, and to continue their pre-study asthma management.

Eligibility Criteria:
Inclusion Criteria:

1. Adults aged 18-80 year (smokers, ex-smokers and non-smokers)
2. Confirmed asthma as per Global Initiative for Asthma (GINA) guidelines 2015\[4\] with characteristic symptoms and at least one of the following:

   * Airflow limitation - FEV1/FVC \< 70% (at any time in the past) and 12% and 200ml increase in FEV1 in the preceding 5 years either:

     i. After inhaled/nebulised bronchodilator or 4+ weeks of anti- inflammatory treatment ii. Between visits
   * Positive bronchial challenge in the preceding 5 years:

   I. Histamine or methacholine provocation concentration causing a 20% drop in FEV1 (PC20) \<8mg/ml ii. Provoking dose of mannitol required to cause a drop in FEV1 of 15% (PD15) mannitol \<635mg
3. Difficult asthma defined as per Scottish Intercollegiate Guidelines Network(SIGN)/British Thoracic Society(BTS) guideline 2014 as persistent symptoms and/or frequent asthma attacks despite treatment at step 4 or step 5 with either:

   * ACQ6\>1.5
   * ≥2 systemic corticosteroid boosts in previous year
   * ≥1 hospitalization in previous year
4. BMI≥25 kg/m2
5. MRC dyspnoea scale ≥3/5

Exclusion Criteria:

1. ICU admission +/- mechanical ventilation in the previous year for asthma exacerbation
2. Respiratory tract infection requiring antibiotics or asthma exacerbation requiring corticosteroid boost in preceding 4 weeks
3. Significant respiratory or other co-morbidity likely to influence the conduct of the study
4. Pregnancy and breast feeding
5. Severe and/or unstable cardiac disease
6. Impaired mobility that impacts on ability to participate in physical training
7. Recent (within the preceding 6 months) commencement of antifungal, biologic (omalizumab, lebrikizumab, mepolizumab) or Airsonett device; eligible if on treatment for \>6months or discontinued \>6 months ago.