Effect of inhaled disodium cromoglycate and albuterol on energy cost of running in asthmatic children.
The purpose of this study is to evaluate the effect of disodium cromoglycate and albuterol on energy cost of running, gas exchange, and ventilation during maximal exercise in children with exercise-induced asthma (EIA). Twelve children (7.1-15.5 years old) with a history of mild to moderate asthma and EIA performed three maximal exercise tests on a treadmill: 1) test A, without premedication; 2) test B, after premedication with inhaled disodium cromoglycate (DSCG) (40 mg); 3) test C, after premedication with inhaled albuterol (200 micrograms). The energy cost of running was calculated at each minute of exercise. None of the children were limited by dyspnea during the run. The post-exercise fall in FEVi after test A was greater than 20% for each child, the mean fall being 32.8 +/- 11.6%, in comparison with 12.6 +/- 8.9% after test B (P less than 0.001) and 2.5 +/- 5.3% after test C (P less than 0.001). There was no difference in the baseline oxygen uptake for the three tests. Maximum oxygen uptake (VO2 peak) decreased from 43.9 +/- 7.7 mL/min/kg in test A to 37.7 +/- 6.0 mL/min/kg in test B (P less than 0.01) and 39.1 +/- 7.2 mL/min/kg in test C (P less than 0.05). Ventilatory anaerobic threshold in tests B and C was significantly lower than in test A (P less than 0.01). Ventilation (L/min) and energy cost of running (O2 mL/kg/m) were significantly lower in tests B and C than in test A at comparable times. Running time was longer in B and C (P less than 0.05) with respect to A.(ABSTRACT TRUNCATED AT 250 WORDS)
Zanconato
S
S
Department of Pediatrics, University of Padua, Italy.
Baraldi
E
E
Santuz
P
P
Magagnin
G
G
Zacchello
F
F
D000280:Administration, Inhalation; D000293:Adolescent; D000420:Albuterol / Q000008:administration & dosage / Q000494:pharmacology*; D001249:Asthma / Q000188:drug therapy / Q000503:physiopathology*; D002648:Child; D004205:Cromolyn Sodium / Q000008:administration & dosage / Q000494:pharmacology*; D004734:Energy Metabolism / Q000187:drug effects*; D005260:Female; D005541:Forced Expiratory Volume / Q000187:drug effects; D006339:Heart Rate; D006801:Humans; D008297:Male; D010100:Oxygen / Q000378:metabolism; D012420:Running
D004205:Cromolyn Sodium; D000420:Albuterol; D010100:Oxygen