Asthma and obesity: Epidemiological data in young adults

In recent years, several studies have found an increase in the prevalence of asthma among obese patients, but the exact nature of this association has not been fully elucidated. The aim of this study was to assess the association between asthma and obesity in 23- to 25-year-old Brazilian adults. This was a cross-sectional analysis of 1922 men and women. Subjects completed a translated questionnaire from the European Community Respiratory Health Survey and underwent spirometry and a bronchial challenge test. Weight, height and waist circumference were measured. Multiple logistic regression analysis was carried out to assess the association of variables related to obesity and asthma, defined by the presence of symptoms and bronchial hyperresponsiveness (BHR). A self-report of a previous physician diagnosis of asthma was separately analyzed as also were socioeconomic characteristics, schooling, physical activity, smoking status, anthropometry and spirometry. No association was detected between asthma confirmed by BHR and obesity indicators: odds ratio (OR)= 1.076 (95% CI: 0.689 - 1.680) for obesity assessed by body mass index ≥ 30 kg/m 2 ; OR = 0.947 (95% CI: 0.686-1.308) by abnormal waist circumference and OR = 1.019 (95% CI: 0.740-1.404) by waist-to-height ratio ≥ 0.5. A previous diagnosis of asthma revealed association with obesity: OR = 1.480 (95% CI: 1.014-2.161) for obesity assessed by body mass index ≥ 30 kg/m 2 ; OR = 1.413 (95% CI: 1.084-1.841) by abnormal waist circumference and OR = 1.477 (95% CI: 1.133-1.926) by waist-to-height ratio ≥ 0.5. Our findings did not support a connection between asthma confirmed by BHR and obesity, but obesity was associated with self-report of a previous physician diagnosis of asthma.