2001 OPEN FORUM Abstracts
EVALUATION OF EXERCISE-INDUCEDBRONCHOSPASM AND OBESITY IN ADOLESCENTS.
R. Randall Baker,PhD, RRT, RCPT; Matthew C. Humphries, BS; Dennis R. Ownby, MD; Paule Barbeau,PhD; and Bernard Gutin, PhD. Medical College of Georgia, Augusta, GA.
BACKGROUND: Exercise intoleranceoccurs when subject responses to an exercise challenge fail to achieve age-and gender-specific norms. This condition can be associated with exercise-inducedbronchospasm (EIB) and sedentary behavior. In addition to limiting exercisecapacity, physical inactivity frequently leads to obesity. The incidence ofboth EIB and obesity are increasing among American youth. The purposes of thispreliminary study were to (1) assess the effect of a modified symptom-limited,maximal oxygen consumption exercise test on detecting EIB, and (2) examine theprevalence of obesity and EIB in a sample of high school students.
Methods: We tested 28 students14 to 18 years of age recruited from local high schools enrolled in an ongoingstudy that is examining relationships of level of fitness and fatness to variouscardiovascular disease risk factors. Inclusion criteria included ethnicity ofeither white or African-American and the absence of chronic cardiovascular conditions.Each student participated in a maximal oxygen consumption treadmill test. Thetest ramp was designed for students to approach their maximum heart rate within10 minutes. Each test was terminated when either a heart rate of 200 beats/minutewas achieved or when the student could no longer continue. Spirometry was performedimmediately prior to and five minutes post exercise using the best of threetrials. Body mass index (BMI) was calculated as weight in kilograms/height inmeter2.
Results: Post-exercise spirometrywas successfully completed in 79% (n =22) of subjects. Fourteen percent (3 of22) of subjects experienced EIB, as demonstrated by a post-exercise fall inFEV1 of > 12%. Five of 28 subjects (18%) were obese havinga BMI that was > the 95th percentile for age and genderor > 30 kg/m2. There were no significant differences between meanbaseline FVC, FEV1, FEV1/FVC ratio, and FEF25%-75% valuesin obese and non-obese subjects using one-tailed T-tests. In addition, Pearsoncorrelation coefficients among BMI and baseline lung function parameters wereweak and not significant.
CONCLUSION: Our findings demonstratethat the exercise challenge used in this protocol is sufficient to elicit EIB.In addition, the data indicate a substantial rate of both EIB and obesity inthis sample of high school students. However, there was no significant associationbetween obesity and EIB.