Exercise-induced asthma. Is gastroesophageal reflux a factor?

An acid-induced cholinergic esophagobronchial reflex has been described whereby acid refluxing into the esophagus causes bronchospasm. Reports of exertional gastroesophageal acid reflux prompted us to study the possibility that exercise-induced asthma (EIA) could be related to gastroesophageal reflux (GER). Following an overnight fast, 10 athletes with a history of EIA (nine men, one woman; mean age 31) were studied. Continuous monitoring of intraesophageal pH and motility, ECG, and arterial oxygen saturation was done. After baseline monitoring at rest for 15 min, subjects underwent treadmill exercise for 10 min followed by continuous monitoring for 30 min after exercise. Spirometry was done at baseline prior to exercise, then repeated every 5 min after exercise for 30 min. Two subjects were retested at a later date following a standard test meal. All 10 subjects demonstrated a decrease in FEV1 in response to exercise, but only half met criteria for EIA. Although 60% (6/10) showed some evidence GER, only three subjects demonstrated a pathologic degree of GER. In the two subjects retested postprandially, change in FEV1 was no different in one and improved in the other despite worsening of GER in both. There was no significant correlations between GER and EIA (P = 0.2). EIA correlated inversely with amplitude of esophageal contractions (P = 0.029) and was directly related to the percentage of multipeaked contractions and the duration of peristaltic contractions (P = 0.08). EIA is not associated with exertional GER.