EXERCISE-INDUCED BRONCHOSPASM IN NONASTHMATIC OBESE CHILDREN

The frequency, degree, and pattern of bronchial reactivity to exercise were compared in 13 obese and 14 control children, ages 6 to 10 years , with no history of asthma. Spirometry was performed before and every three minutes after a seven-minute exercise challenge on a treadmill. There were 11 obese children and 6 controls who had at least a 15% fa ll in at least one of three monitored pulmonary function parameters (P <.05). The group mean percentage falls in FEV1 and FEF25%-75% were sig nificantly greater in the obese group than in the controls. The patter n of bronchospasm, occurring soon after the exercise challenge, is con sistent with that found in the known asthmatic population. A significa nt correlation was found between triceps skin-fold thickness and degre e of fall in FEF25%-75%(r=.55, P<.005). This study demonstrated that s ignificantly greater frequency and degree of bronchospasm of the small er airways occur in obese children, partially related to the amount of subcutaneous fat. Whether exercise-induced bronchospasm leads to exer cise avoidance and obesity or whether obesity causes or enhances bronc hial hyperreactivity to exercise requires further study.