Abstract
Rationale: Obesity affects asthma development, severity, and treatment response. Understanding how obesity influences symptoms, QOL and asthma characteristics is thus necessary to optimize management for this phonotype.
Methods: 186 adult patients with mild-to-moderate persistent asthma were enrolled in this study, from which 25 patients whose BMI of > 25 kg/m2 and 25 normal weight patients were randomly selected. Patients completed ACT and underwent comprehensive pulmonary function testing. Blood samples were collected to measure adipocytokines including IL-6, leptin, adiponectin, PAI-1 and TNF-α. Inflammatory cell counts in induced sputum and NO contents in exhaled air were measured. We also assessed the response to 12-week treatment with FBC.
Results: Overweight patients were more likely to be women (p = 0.026), and had older age of disease onset (p = 0.022), lower ACT scores (p = 0.045) and lower serum IgE (p = 0.042). FRC and ERV were less in overweight patients than in normal weight patients (both p < 0.05), but there were no differences in FVC, FEV1, TLC and RV between two groups. In overweight patients, IL-6, leptin and PAI-1 levels were lower (each p < 0.04), and there were significant positive correlation between plasma leptin concentration and sputum eosinophil number and ECP contents. After the treatment, among asthma-related measures, the responses of FEV1 and ACT scores were poorer in overweight patients (both p < 0.05).
Conclusion: Overweight is an important phonotypic determinant in asthma. The increased levels of leptin might play a role in eosinophilic airway inflammation, and the responses to inhaled corticosteroid are attenuated in overweight patients.
- © 2013 ERS