Characterisation of Asthma in Obese Subjects

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details. Identifier: NCT00532831
Recruitment Status : Completed
First Posted : September 20, 2007
Last Update Posted : February 22, 2012
Information provided by (Responsible Party):
Louis-Philippe Boulet, Laval University

September 18, 2007
September 20, 2007
February 22, 2012
August 2005
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Airway response to methacholine [ Time Frame: two weeks ]
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Complete list of historical versions of study NCT00532831 on Archive Site
lung volumes [ Time Frame: Two weeks ]
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Characterisation of Asthma in Obese Subjects
Characterisation of Asthma in Obese Subjects. Relationships Between Asthma and Obesity, Potential Mechanisms by Which Obesity Can Contribute to Asthma and Modify Treatment Responses

Our hypothesis:

Obese subjects with a physician's made diagnosis of asthma have a poorer asthma control than asthmatics with normal weight, less variability of peak expiratory flows (PEF) and bronchodilator response,increased induced sputum and systemic markers of inflammation and an increased prevalence of atopy.

Obese subjects have an increased incidence of co-morbidities such as rhinosinusitis, gastroesophageal reflux and sleep apnea syndrome.

This study aims to determine if, in comparison with asthmatics with a normal weight, paired for age and sex, obese subjects with asthma (all not using anti-inflammatory agents) show:

  • A more uncontrolled asthma, increased health care use and poorer quality of life
  • A reduced response to bronchodilators and diurnal variability of expiratory flows
  • More marked airway inflammation and evidences of a systemic inflammatory response
  • An increased prevalence of co-morbidities which can influence the report of respiratory symptoms or the severity of the disease, such as esophageal reflux symptoms, upper airway disease (rhinitis) and sleep apnea syndrome or other sleep disorder.

Questionnaires on respiratory symptoms, health care use, quality of life, medication and asthma control will be administered and a thoracic examination performed.

Spirometry and bronchodilator response, blood tests for inflammatory parameters, pH measurements in exhaled air condensate and sputum induction will be performed. Peak expiratory flows will be measured and recorded on a diary card during one week.

On the second visit, measures of lung volumes and a methacholine challenge will be performed.

Observational Model: Case Control
Time Perspective: Cross-Sectional
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Retention:   Samples Without DNA
serum plasma
Non-Probability Sample
Subjects wiil be selected from the Hospital asthma primary care clinic and from advertisements in newspapers. Their will be offered to participate to the study
  • Asthma
  • Obesity
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  • Obese asthmatics
    Obese subjects with asthma (on inhaled bd only)
  • Non-obese asthmatics
    Non-obese subjects with asthma(on inhaled bd only)
Lessard A, Turcotte H, Cormier Y, Boulet LP. Obesity and asthma: a specific phenotype? Chest. 2008 Aug;134(2):317-323. doi: 10.1378/chest.07-2959. Epub 2008 Jul 18.

*   Includes publications given by the data provider as well as publications identified by Identifier (NCT Number) in Medline.
Same as current
July 2010
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Inclusion Criteria:

  • aged 18 and over.
  • in good health apart from asthma or obesity as determined by history and physical examination (no other condition which could influence the proposed tests).
  • All will be non smokers or ex- smokers for more than six months with a smoking history of no more than 10 pack- years (i.e., one pack per day or its equivalent for 10 years.)
  • Subjects will have a physician's made diagnosis of asthma and have received a bronchodilator prescription in the last year.

Exclusion Criteria:

  • Use of asthma medications other than bronchodilators
  • Subjects who are, in the opinion of the investigator, mentally or legally
  • incapacitated thus preventing informed consent from being obtained.
  • Subjects having a co-existing illness that precludes them from the trial.
  • Pregnancy or lactation
Sexes Eligible for Study: All
18 Years and older   (Adult, Senior)
Contact information is only displayed when the study is recruiting subjects
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Louis-Philippe Boulet, Laval University
Laval University
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Principal Investigator: Louis-Philippe Boulet, MD Hôpital Laval
Laval University
February 2012