Bariatric and Obstructive Lung Disease Study II

Effects of Obesity on Airway Caliber and Airway Smooth Muscle Tone

The prevalence of obesity and asthma has significantly increased over the past two decades. The purpose of this study is to try and understand the mechanism by which obesity leads to airway hyperresponsiveness (AHR), one of the defining features of asthma. This research is being done to determine how weight or body size affects airway size and airway smooth muscle (ASM) tone and function. The goal of the study will be to look at if and how, weight might affect lung functioning.

The investigators hypothesize that low lung volumes in obesity lead to AHR by reducing airway caliber causing increased ASM tone with impairment in deep inspiration (DI) response similar to what is seen in asthma.

Inclusion Criteria:

• Age 18 years or older
• BMI over 35 kg/m2 (Bariatric) or BMI between 25 and 28 kg/m2 (Control)
• Physician diagnosis of asthma and on active asthma medication (if asthmatic)

Exclusion Criteria:

• Weight greater than 450 lbs
• Unstable cardiovascular disease
• Uncontrolled hypertension
• Renal failure on dialysis
• Cirrhosis
• Pregnant or lactating
• Bleeding disorders or Coumadin use
• Recent hospitalization for asthma in the past 3 months
• Active smoking or more than 10 pack year smoking history