Phenotypic determinants of uncontrolled asthma

Abstract

Background: Although uncontrolled asthma remains frequent, determinants of asthma control are poorly studied.

Objectives: The aim was to estimate the distribution and the phenotypic characteristics of asthma control in 2 groups of subjects defined by the use of inhaled corticosteroids (ICS) in the past 12 months, in the Epidemiological study on the Genetics and Environment of Asthma, bronchial hyperresponsiveness and atopy (EGEA).

Methods: Five hundred one adult current patients with asthma who participated in the follow-up of the EGEA study were included. Asthma control was assessed from survey questions reflecting asthma control, as defined in the 2006 Global Initiative for Asthma guidelines. The factors analyzed were age, sex, educational level, body mass index, active and passive smoking, sensitization to aeroallergens, total IgE, rhinitis, chronic cough/phlegm, and age at asthma onset. Analyses were stratified according to ICS use.

Results: Uncontrolled asthma was more frequent in ICS users (27.6%, 35.0%, and 37.4% with controlled, partly-controlled, and uncontrolled asthma respectively) compared with non-ICS users (60.0%, 23.9%, and 16.1%, respectively). In ICS users, chronic cough or phlegm and female sex were independently and significantly related to uncontrolled asthma. In non-ICS users, high total IgE and sensitization to molds were associated with uncontrolled asthma. Smoking and rhinitis were not associated with asthma control.

Conclusion: Optimal asthma control remained unachieved in the majority of patients with asthma in this study. Factors associated with uncontrolled asthma were different in ICS users (chronic cough/phlegm, female sex) and non-ICS users (high total IgE and sensitization to molds).