Asthma control, adiposity, and adipokines among inner-city adolescents

BackgroundThere is an association between adiposity and asthma prevalence, but the relationship to asthma control is unclear.ObjectivesWe sought to understand the relationships among adiposity, sex, and asthma control in inner-city adolescents with asthma.MethodsWe prospectively followed 368 adolescents with moderate-to-severe asthma (ages 12-20 years) living in 10 urban areas for 1 year. Asthma symptoms and exacerbations were recorded, and pulmonary function and exhaled nitric oxide levels were measured every 6 weeks. Adiposity measures (body mass index [BMI] and dual-energy X-ray absorptiometric scans) were made, and blood was collected for measurement of allergy markers, adiponectin, leptin, TNF-α, IL-6, and C-reactive protein levels.ResultsMore than 60% of female subjects and 50% of male subjects were above the 85th percentile of BMI for age. Higher BMI was associated with more symptom days (R = 0.18, P = .02) and exacerbations (R = 0.18, P = .06) among female subjects only. Adiponectin was inversely related to asthma symptoms (R = −0.18, P < .05) and exacerbations (R = −0.20, P < .05) and positively with FEV1/forced vital capacity ratio (R = 0.15, P < .05) in male subjects only independent of body size. There was no relationship between adiposity or adipokines and total IgE levels, blood eosinophil counts, and exhaled nitric oxide levels. Dual-energy X-ray absorptiometry provided little additional value in relating adiposity to asthma outcome in this population of adolescents.ConclusionAdiposity is associated with poorer asthma control in female subjects. Adiponectin is associated with improved asthma control in male subjects.