Abstract Rationale There are conflicting reports on the associations between physical activity (vs sedentarism) and asthma in children and adolescents. Further, there is an absence of well characterized data differentiating asthma phenotypes between sedentary youth and their more active peers. Methods As part of the Genomics of Obesity-Related Asthma study (GenOAAT), youths ages 6-20 years completed questionnaires assessing weekly physical activity (e.g., bike-riding) and sedentary time (e.g., videogames). We classified participants into quadrants based on active time and sedentary time above/below the median (Fig.1A). Participants also completed spirometry, bronchodilator response, fractional exhaled nitric oxide (FeNO); those with asthma completed the Asthma Control Test (ACT), Asthma Therapy Assessment Questionnaire (ATAQ), and the Pediatric Asthma Quality of Life Questionnaire (PAQLQ). We used multivariable regression models adjusted for age, sex, race, and BMI z-score (BMIz) to assess the differences by activity/sedentarism group. Results We analyzed data from 144 GenOAAT subjects (mean age=14.3 years, 47% female, 82% White, mean BMIz=1.27), including 69 with asthma (cases). In our adjusted analysis, FeNO was lower among more sedentary participants regardless of asthma diagnosis (quadrants B/C/D vs A, β range −15.2 to − 12.6 ppb; p=0.017-0.04). Among children with asthma, there were similar trends for lower total blood eosinophils (β= -150 cells/µL 95%CI -300, 19; p=0.05) and lower bronchodilator response (β= -6.6% 95%CI -12.4, -0.9; p=0.02). In terms of asthma symptoms and quality of life, we found a trend towards lower ATAQ score (β= -1.2 95%CI -2.5, 0.06; p=0.06) with no significant associations for the ACT (β = 1.8 95%CI -1.25, 4.9; p=0.24) or the PAQLQ (β = 0.12 95%CI -0.25, 0.51; p=0.51) in sedentary compared to active children. (Fig. 1B) Of note, the more sedentary participants with asthma (quadrant D) had a trend towards higher BMIz. (β = 1.1 95%CI -0.15, 2.39; p=0.08), BMIz did have significant effect on ACT scores (β = 1.1 95%CI -1.7, -0.47; p=0.001) even when controlling for level of activity. Conclusion In this cohort, higher sedentary play and lower physical activity were associated with lower bronchodilator response, lower FeNO, and lower eosinophil counts. These findings suggest that youth with asthma who engage in less active play and more sedentary time may have an asthma phenotype that is less atopic and less responsive to albuterol. We found a trend towards better ATAQ scores but no associations with the ACT or PAQLQ; we will further explore these conflicting associations. This abstract is funded by: HL149693 (NIH)
Averill et al. (Fri,) studied this question.