Role of Cysteinyl Leukotrienes in the Pathogenesis of Asthma in Obesity
Trial Snapshot
- Phase
- Not Applicable
- Status
- Completed
- Sponsor
- University of Michigan
- Enrollment
- 117
- Locations
- 1
- Primary Endpoint
- Plasma Leptin
Study Overview
Brief Summary
The purpose of this study is to examine whether there are higher levels of cysteinyl leukotrienes in obese subjects than in non-obese subjects. Cysteinyl leukotrienes are pro-inflammatory substances that cause asthma by narrowing the airways of the lung. The investigators want to see if subjects with increased fat stores and therefore increased leptin, which is a fat-related protein that regulates leukotrienes, have increased levels of leukotrienes in the blood, lung and urine. The investigators would also like to determine the relationship between cysteinyl leukotrienes and exhaled nitric oxide levels in asthmatics with and without obesity. Nitric oxide is anti-inflammatory and suppresses leukotriene synthesis.
Detailed Description
This is a cross-sectional observational study to characterize the association between obese asthmatics and the inflammatory mediators cysteinyl leukotrienes. Our hypothesis is that altered adipokine levels in obesity result in augmented cysteinyl leukotriene synthesis that play a significant role in the pathogenesis of asthma in these subjects.
Study Design
- Study Type
- Observational
- Observational Model
- Case Control
- Time Perspective
- Cross Sectional
Eligibility Criteria
- Ages
- 18 Years to 65 Years (Adult, Older Adult)
- Sex
- All
- Accepts Healthy Volunteers
- Yes
Inclusion Criteria
- •18-65 yr old adults with asthma, non-smoking for at least one year
- •Healthy non-smoking adults, aged 18-65 without asthma
- •Heavy subjects with BMI > 30 kg/m2
- •Subjects with normal weight (BMI between 20-25 kg/m2)
- •Subject not taking anti-leukotriene therapy (Singulair, Accolate, Zyflo)
Exclusion Criteria
- •No chronic oral steroid use
- •No recent history of infection
- •No recent history of flare of lung disease
Outcomes
Primary Outcomes
Plasma Leptin
Time Frame: Observational: one time point from a blood draw after more than 6 hours fasting
Measurement of plasma leptin in obese and non obese asthmatics and non-asthmatic subjects from a single blood draw.
Urine Cysteinyl Leukotriene Per Creatinine
Time Frame: sample taken over 5 minutes or less
Urine inflammatory mediators measured from a single urine sample
Ratio U Cys-LT/FeNO
Time Frame: sample taken over 5 minutes or less
Responsiveness to leukotriene modifier medication by measuring the urine cysteinyl leukotriene/exhaled nitric oxide ratio
Exhaled Nitric Oxide (FeNO)
Time Frame: Observational: Two exhalations within 1 minute
Exhaled breath nitic oxide ppb (averaged values from 2 exhalations per participant)
Secondary Outcomes
No secondary outcomes reported
Investigators
Michael Coffey
Associate Professor Internal Medicine, Pulmonary Division
University of Michigan