Increased body mass index does not lead to a worsening of asthma control in a large adult asthmatic population in Spain.

■ Abstract Background: Data on the association between obesity and asthma control are confl icting. We performed an analysis to elucidate the association between body mass index (BMI) and asthma control in a large sample of asthmatics. Materials and Methods: Data were obtained from a previous study in which the Asthma Control Questionnaire (ACQ) and Asthma Control Test (ACT) were validated for a Spanish population. The study sample comprised 607 adult (≥18 years) asthmatic patients (61% female), of whom 235 (39%) had mild-persistent asthma, 246 (41%) had moderate-persistent asthma, and 126 (21%) had severe-persistent asthma. Results: The analysis showed a signifi cant but very low correlation between BMI and ACQ-forced expiratory volume in the fi rst second of expiration (FEV1) (r=0.1, P=.007) and ACQ-peak expiratory fl ow (PEF) (r=0.1, P=.010), but not ACQ-without lung function (wLF) (r=0.06, P=.116) or ACT. No signifi cant association was found between BMI and asthma control as defi ned by physicians or according to ACT or ACQ (ACQ-FEV1, ACQ-PEF and ACQ-wLF) scores. We found no signifi cant associations between ACT, ACQs (ACQ-FEV1, ACQ-PEF and ACQ-wLF), and BMI when BMI was classifi ed as low (BMI, 34.9 kg/m 2 ). However, the percentage of patients with poor control was slightly greater in patients with low BMI and obesity. Conclusions: Using specifi c and validated tools, and in the context of clinical practice, this study did not fi nd a relevant association between BMI and asthma control.