Physical Activity does not Modify the Relationship between Asthma and Obesity in African American Youth

Abstract

Asthma is an important health issue in adolescents, particularly among African Americans (AA). Previous research has identified obesity as a risk factor for childhood asthma, however, less research has examined whether asthma predicts obesity. It is plausible that the presence of asthma symptoms may contribute to inactivity and subsequent obesity risk in AA youth. PURPOSE: The purpose of this study was to assess the cross-sectional relationships between the presence of asthma symptoms, weight status, moderate-vigorous physical activity (MVPA) and sedentary time (SED) among AA adolescents. METHODS: A community-based sample of 163 AA youth (55% female, 31% obese, ages 11-18 years), recruited from southeast Michigan were included in this analysis. Asthma symptoms were evaluated and given a single score from 0 (no symptoms ever) to 11 (all symptoms often) using the International Study of Asthma and Allergies in Children’s Phase Three questionnaire. MVPA and SED were measured via accelerometry. Weight status was assessed via body mass index (BMI) where weight and height were measured via an electronic scale and stadiometer, respectively. RESULTS: Of the 163 adolescents included in the analysis, 68 reported no symptoms of asthma (54% female, 22% obese). T-tests revealed those with no symptoms of asthma engaged in less MVPA (no symptom: 12.5±0.1min; ≥ one symptom: 13.6±0.1min, p<0.001) and more SED (no symptom: 758.3±1.2min; ≥ one symptom: 753.8±1.0min, p=0.004) compared to adolescents with one or more symptoms of asthma. After accounting for the confounding effects of sex, parental education, and pubertal development; asthma symptom score was positively associated with BMI (β=0.6±0.2, p=0.004). When MVPA and SED were included in the model, the relationship between asthma symptom score and BMI remained significant (β=0.5±0.2, p=0.007). CONCLUSION: A higher presence of asthma symptoms predicted increased weight status in AA adolescents. Physical activity participation and sedentary time did not modify this relationship, suggesting that other factors contribute to the increased obesity risk in children exhibiting asthma symptoms. Longitudinal studies are needed to better understand the relationship between asthma and obesity in AA adolescents.