Study of the Physiology of the Asthma of the Obese Subjects. Breathing Obesity Asthma Study (BOA) (BOA)

September 17, 2013 updated by: Assistance Publique - Hôpitaux de Paris

Pathophysiological Study of Obesity-related Asthma

Asthma is more frequent in obese women, but the mechanisms underlying the causes of this increased frequency are unknown and are different from usual asthma pathophysiology (associated with allergy). Obesity is known to influence ventilation; our hypothesis is that the normal variability of ventilation is decreased in obese patients, and that this decrease is responsible for an increased reactivity of their airway to non specific stimuli. In this observational study, breathing variability will be studied using polygraphy (an investigation that is made in these women to detect nocturnal apneas), and airway reactivity is studied between pulmonary function tests that are made before bariatric surgery.

Study Overview

Status

Completed

Conditions

Detailed Description

Background : An increase in asthma prevalence (or asthma-like symptoms) has been established in obese subjects, especially women. The aim of this pathophysiological study is to evaluate whether the modifications of respiratory mechanics due to severe obesity (Body Mass Index [BMI]>35) may explain the increase in asthma prevalence. Our hypothesis is that a decrease in variability of tidal breathing (evaluated by the coefficient of variation of Tidal volume: CVTV) (which traduces a physiological response to the increased work of breathing) associated with a decrease in the frequency of deep inhalations (FDI) (physiological sighs). The bronchodilatory and bronchoprotective roles of these deep inhalations have been demonstrated. The avoidance of deep inhalations during 10 minutes in healthy subjects is responsible for a non specific transient airway hyperresponsiveness (AHR) to methacholine. Consequently, obesity-related asthma could be due to the loss of bronchoprotective effect of deep inhalations.

Aims: The aim of this study is to evaluate whether 1) the variability of their diurnal ventilation (based on the measurement of CVTV and FDI) in three groups of women: obese with AHR, obese without AHR and healthy non obese (main objective), 2) obesity-related asthma pathophysiology is linked to atopy, and 3) obese asthmatic women have a greater decrease in ventilation variability as compared to non asthmatic obese women (secondary objectives).

Methods: The prevalence of AHR and confirmed asthma (international clinical and functional definition) are determined based on pulmonary function test (spirometry, volume determinations, arterial blood gas, measurement of the resistance of the respiratory system with evaluation of the response to deep inhalation, methacholine challenge, exhaled NO measurement, nocturnal polygraphy and oeso-gastroscopy) results obtained from 150 obese (BMI > 35). The FDI and CVTV will be determined based on the tidal volume obtained from thoracic and abdominal plethysmography inductance measurements during the polygraphy. A nocturnal polygraphy is systematically done in these women to search for a Sleep Apnea Syndrome. 30 healthy (non asthmatic, normal exhaled NO value, BMI 18.5 to 25) women will constitute a control group. The size of the groups have been calculated based on literature data concerning the FDI and CVTV.

Analysis criteria: The prevalences of asthma (or asthma-like symptoms) and AHR will be of 30% and 50% (based on a personal preliminary study), respectively. The FDI and CVTV will be compared in obese women with and without AHR and in healthy women (primary objective), and subsequently in obese asthmatic women and obese non asthmatic women. The measurement of exhaled NO and the bronchomotor effect of deep inhalation will allow the determination of underlying pathophysiology of obesity-related asthma (secondary objective).

Perspectives: If our hypothesis is verified, obesity treatment will become part of the management of asthma in women.

Study Type

Observational

Enrollment (Actual)

204

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • France
      • Paris, France
        • Department of Physiology, Hôpital Européen Georges Pompidou

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

18 years to 55 years (Adult)

Accepts Healthy Volunteers

Yes

Genders Eligible for Study

Female

Sampling Method

Non-Probability Sample

Study Population

obese with AHR, obese without AHR and healthy non obese

Description

Inclusion Criteria:

  • female
  • age>18 and < 55 years
  • BMI>35 (< 25 for healthy women)
  • planned bariatric surgery

Exclusion Criteria:

  • sleep apnea syndrome
  • pregnant or breast-feeding women
  • No affiliation or non beneficiary of the National Health Insurance

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

Cohorts and Interventions

Group / Cohort
healthy volunteers
obese

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Time Frame
compare the variability of the diurnal ventilation (based on the measurement of CVTV and FDI) in three groups of women: obese with AHR, obese without AHR and healthy non obese.
Time Frame: 24 hours
24 hours

Secondary Outcome Measures

Outcome Measure
Time Frame
evaluate if the obesity-related asthma pathophysiology is linked to atopy, and if obese asthmatic women have a greater decrease in ventilation variability as compared to non asthmatic obese women
Time Frame: 24 hours
24 hours

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Assistance Publique - Hôpitaux de Paris

Investigators

  • Principal Investigator: DELCLAUX MD Christophe, PhD, Department of Physiology, Hôpital Européen Georges Pompidou

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start

January 1, 2008

Primary Completion (Actual)

June 1, 2010

Study Completion (Actual)

November 1, 2010

Study Registration Dates

First Submitted

December 19, 2007

First Submitted That Met QC Criteria

December 19, 2007

First Posted (Estimate)

December 20, 2007

Study Record Updates

Last Update Posted (Estimate)

September 18, 2013

Last Update Submitted That Met QC Criteria

September 17, 2013

Last Verified

December 1, 2007

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • P061010

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

Clinical Trials on Obesity

Search Similar Trials

Sponsors and Collaborators

Medical Conditions

Drug Interventions

CROs by country

CROs in Paraguay

Conditions

Rare Diseases

Drug Interventions

Dietary Supplements

Sponsor/Collaborators

Locations

Subscribe