Dissociation of symptom scores and bronchial hyperreactivity: study in asthmatic children on long-term treatment with inhaled beclomethasone dipropionate

Abstract

The aim of the study was to evaluate the effects of inhaled steroids (IS) on the improvement of clinical asthma symptoms and on the decrease in bronchial hyperreactivity (BHR). Twenty-four children with severe asthma were given 1,000 micrograms beclomethasone dipropionate (BDP) daily and compared with ten asthmatic control children. The study included the evaluation of daily clinical score, of exercise induced asthma, of bronchial obstruction (forced expiratory volume in 1 sec, FEV1), and of BHR at months 0, 1, 2-3, and 4-5 (M0, M1, M2-3, and M4-5). BHR was assessed by standardized inhaled carbachol provocation measuring plethysmographic specific airway resistance (SRaw). The carbachol dose causing a 40% decrease in specific conductance (SGaw) was determined (PD40 SGaw). Clinical scores decreased at M1 (P less than 0.01) and throughout the study. FEV1 increased at M1 (P less than 0.05), M2-3 (P less than 0.01), and M4-5 (P less than 0.05) compared to M0. PD40 SGaw only increased significantly at M1 and M2-3. No individual correlation was found between clinical scores and PD40 SGaw at any testing, or between the decrease of clinical scores and the decrease of BHR. We conclude that bronchoconstrictive challenge tests do not adequately assess the clinical efficacy of IS. In clinical practice non-specific BHR should be preferentially measured for diagnosing atypical forms of asthma.