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

This study has been completed.
Sponsor:
Information provided by (Responsible Party):
Assistance Publique - Hôpitaux de Paris
ClinicalTrials.gov Identifier:
NCT00577733
First received: December 19, 2007
Last updated: September 17, 2013
Last verified: December 2007
  Purpose

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.


Condition
Asthma
Obesity

Study Type: Observational
Study Design: Time Perspective: Prospective
Official Title: Pathophysiological Study of Obesity-related Asthma

Resource links provided by NLM:


Further study details as provided by Assistance Publique - Hôpitaux de Paris:

Primary Outcome Measures:
  • 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 ] [ Designated as safety issue: No ]

Secondary Outcome Measures:
  • 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 ] [ Designated as safety issue: No ]

Enrollment: 204
Study Start Date: January 2008
Study Completion Date: November 2010
Primary Completion Date: June 2010 (Final data collection date for primary outcome measure)
Groups/Cohorts
obese
obese
healthy volunteers
healthy volunteers

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.

  Eligibility

Ages Eligible for Study:   18 Years to 55 Years
Genders Eligible for Study:   Female
Accepts Healthy Volunteers:   Yes
Sampling Method:   Non-Probability Sample
Study Population

obese with AHR, obese without AHR and healthy non obese

Criteria

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
  Contacts and Locations
Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the Contacts provided below. For general information, see Learn About Clinical Studies.

Please refer to this study by its ClinicalTrials.gov identifier: NCT00577733

Locations
France
Department of Physiology, Hôpital Européen Georges Pompidou
Paris, France
Sponsors and Collaborators
Assistance Publique - Hôpitaux de Paris
Investigators
Principal Investigator: DELCLAUX MD Christophe, PhD Department of Physiology, Hôpital Européen Georges Pompidou
  More Information

No publications provided

Responsible Party: Assistance Publique - Hôpitaux de Paris
ClinicalTrials.gov Identifier: NCT00577733     History of Changes
Other Study ID Numbers: P061010
Study First Received: December 19, 2007
Last Updated: September 17, 2013
Health Authority: France: Ministry of Health

Keywords provided by Assistance Publique - Hôpitaux de Paris:
Pulmonary function test
Methacholine challenge
Breathing variability
Polygraphy

Additional relevant MeSH terms:
Asthma
Obesity
Body Weight
Bronchial Diseases
Hypersensitivity
Hypersensitivity, Immediate
Immune System Diseases
Lung Diseases
Lung Diseases, Obstructive
Nutrition Disorders
Overnutrition
Overweight
Respiratory Hypersensitivity
Respiratory Tract Diseases
Signs and Symptoms

ClinicalTrials.gov processed this record on November 25, 2014