Antioxidant Therapy in Lean and Obese Asthmatics

Study Overview
=================
Brief Summary
-----------------
This project will assess the effectiveness of antioxidant supplementation with common vitamins A, C, E and selenium in controlling asthma symptoms among lean and obese asthmatics. This project may improve our ability to treat asthma and our understanding of the link between nutritional antioxidants and asthma.

Detailed Description
-----------------
Asthma & Obesity are both growing public health crises that also may be critically interrelated for many patients. Obesity increases the risk for asthma in both adults and children, and obesity increases the severity of existing asthma. Obesity leads to increased systemic oxidative stress, however little is know about obesity-related oxidative stress within the airway. Since oxidative stress contributes to the pathogenesis of asthma, obesity may influence asthma risk and severity through this mechanism. Asthmatics have low serum antioxidant activity. There is conflicting evidence about whether or not antioxidant supplementation reduces asthma severity. This may be related to asthma's heterogeneous nature. Antioxidant supplementation may be effective in select subgroups that have the greater oxidative stress, such as asthmatics with occupational exposures or obesity. In fact, the evidence supporting antioxidant supplementation in asthma involved subjects with oxidant-related triggers. We hypothesize that obesity-related oxidant stress puts asthmatics at risk for increased airway oxidative stress and greater asthma severity. We hypothesize that supplementation with common antioxidants will significantly reduce airway inflammation and oxidative stress, and lead to improved pulmonary function and daily asthma control. This pilot study is designed as a randomized, double-blinded, placebo-controlled, parallel intervention trial involving lean and obese adolescents and young adults with asthma. After the 2-week run-in period, all subjects will undergo baseline testing (see figure 1). At randomization they will receive either placebo or a multivitamin antioxidant for 42 days. At the end of the 42 day intervention all subjects will undergo final testing. Primary Hypothesis: In young asthmatics, antioxidant supplementation increases plasma and airway antioxidant levels leading to improved lung function and asthma control. Secondary Hypotheses: 1) Obesity-related systemic oxidant stress is associated with increased oxidative stress within the airway. 2) Antioxidant supplementation will lead to greater improvements in asthma control among obese compared to lean (not underweight) asthmatics. 3) Antioxidant supplementation will lead to greater improvements in airway markers of inflammation and oxidative stress among obese compared to lean asthmatics. We will assess asthma control and lung function before and after therapy.

Official Title
-----------------
Phase 2 Study of Antioxidant Therapy in Lean and Obese Asthmatics

Conditions
-----------------
Asthma

Intervention / Treatment
-----------------
* Dietary Supplement: Vitamins A, E, C & Selenium
* Dietary Supplement: Placebo


Participation Criteria
=================
Eligibility Criteria
-----------------
Inclusion Criteria: age 12-25, physician-diagnosed persistent asthma on daily controller therapy, FEV1% >= 60% predicted, Lung responsiveness (>= 12% BD reversibility or PC20 MCT <= 16mg/ml) Exclusion Criteria: taking daily MVI, chronic oral steroid therapy, BMI<20th percentile, smoking history, pregnancy, milk allergy, celiac disease

Ages Eligible for Study
-----------------
Minimum Age: 12 Years
Maximum Age: 25 Years

Sexes Eligible for Study
-----------------
All

Accepts Healthy Volunteers
-----------------
No

Study Plan
=================
How is the study designed?
-----------------

Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Quadruple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: Antioxidant arm<br>Two capsules twice daily (total daily dose = Vitamin A 10000 IU, Vitamin C 1200mg, Vitamin E 400 IU, Selenium 300mcg) | Dietary Supplement: Vitamins A, E, C & Selenium<br>* daily dose = Vitamin A 10000 IU (beta carotene), Vitamin E 400 IU, Vitamin C 1200mg, and Selenium 300mcg.<br>|
| Placebo Comparator: Placebo arm<br>two capsules twice daily (total daily dose = 1200mg whey protein, 800mg microcrystalline cellulose) | Dietary Supplement: Placebo<br>* total daily dose = 1200mg whey protein, 800mg microcrystalline cellulose<br>|

What is the study measuring?
-----------------
Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change in Asthma Control Questionnaire (Juniper)- (ACQ) | ACQ is a 7 component test that includes 6 responses elliciting control of asthma symptoms plus one component based on FEV1 (spirometry). The score ranges from 0-6, with a higher score suggesting greater asthma symptoms. | 6 weeks | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change in Asthma Symptom Utility Index | Questionnaire assessing patient reported asthma symptoms from the previous 2 weeks. Score ranges from 0 to 1 with a higher score suggesting better asthma control. | 6 weeks | 
| change in FEV1 | Spirometric measure of volume expired in 1 second. | 6 weeks | 

 Terms related to the study
=================
Keywords Provided by Centre Hospitalier Valida
-----------------
asthma, obesity, nutrition, antioxidant