Distal airway impairment in obese normoreactive women.
BACKGROUND
Asthma-like symptoms are frequent in overweight and obesity, but the mechanism is unclear when airway hyperresponsiveness (AHR) is lacking. In this study, we focused on obese women with a clinical suspicion of asthma but negative methacholine challenge and tested distal airway hyperreactivity, explored by Forced Vital Capacity dose-response slope (FVC DRS).


OBJECTIVE
To question AHR at the distal airway level in obese women.


METHODS
A total of 293 symptomatic obese and nonobese women free of treatment were investigated. Methacholine challenge tests were undertaken, and patients were divided according to their results to the test. In hyperreactive and nonhyperreactive patients and in our total population, correlations, regression analyses, and analyses of covariance were performed to compare distal airway hyperreactivity in three groups of body mass index (BMI).


RESULTS
After adjusting for age and baseline respiratory values, the relationship between FVC and FEV1 (forced expiratory volume in one second) DRS was influenced by BMI, with a lower slope in obese than overweight and normal patients in our total population (P = 0.008) and in our nonhyperreactive one (P = 0.028).


CONCLUSIONS
Distal airway hyperresponsiveness was observed in symptomatic wheezing obese women negative to methacholine challenge.
Department of Respiratory Diseases, Montpellier University Hospital and INSERM U106, Montpellier University, 34090 Montpellier, France.
Grégory
G
Marin
Anne Sophie
AS
Gamez
Nicolas
N
Molinari
Djamila
D
Kacimi
Isabelle
I
Vachier
Fabrice
F
Paganin
Pascal
P
Chanez
Arnaud
A
Bourdin
D000328:Adult; D001249:Asthma / Q000150:complications / Q000175:diagnosis* / Q000473:pathology*; D015992:Body Mass Index; D001985:Bronchial Provocation Tests; D005260:Female; D005541:Forced Expiratory Volume; D006801:Humans; D008297:Male; D016210:Methacholine Chloride / Q000008:administration & dosage; D008875:Middle Aged; D009765:Obesity / Q000150:complications / Q000473:pathology*; D050177:Overweight / Q000150:complications / Q000473:pathology; D014797:Vital Capacity
D016210:Methacholine Chloride