A comparative study evaluating c-reactive protein, sputum eosinophils and forced expiratory volume in one second in obese and nonobese asthmatics

Abstract

Introduction: Asthma and obesity are considered inflammatory disorders. Inflammatory markers — sputum eosinophils, C-reactive protein (CRP) and the forced expiratory volume in one second (FEV1) were analysed to find their association in obese asthmatics and compared with their asthma control test (ACT) to understand these parameters in this phenotype. Material and methods: After completing the asthma control test (ACT), the CRP, FEV1 and sputum eosinophils of sixty asthmatics were compared to find the association of them in obese and nonobese asthmatics and contrasted with their ACT. The data were analysed using IBM SPSS V20.0, Mann-Whitney U test (non-parametric test), Pearson’s correlation coefficient and Fisher’s exact test. Results: We found significant differences for CRP (P = 0.001) and sputum eosinophils (P = 0.001) between obese and nonobese asthmatics, both higher in obese asthmatics and with a significant association with body mass index (BMI) (P < 0.05). The FEV1 levels were independent of the BMI levels of asthmatics. There was a significant correlation between the CRP and sputum eosin-ophils (0.52, P = 0.001) for all asthmatics. There was no significant correlation between FEV1 and sputum eosinophils (nonobese P = 0.120, obese P = 0.388) and between FEV1 and CRP (obese P = 0.423, nonobese P = 0.358) in both obese and nonobese asthmatics. Obesity had an association (P = 0.001) with ACT scores (≤ 19). Conclusions: Sputum eosinophils and CRP were raised in obese asthmatics and had a positive association with BMI. Obese asthmatics had a poorer subjective asthma control than nonobese asthmatics despite FEV1 being independent of the BMI levels. Measuring the systemic inflammatory markers could help in additional interventions in reducing systemic inflammation and thus possibly facilitating better symptom control.