Effect of esophageal and gastric distention on bronchial hyper-responsiveness in patients with bronchial asthma.

ABSTRACT

OBJECTIVE: Over-eating is said to aggravate asthma though the mechanism is still unclear. We tried to study the mechanism by causing distention in oesophagus and stomach. METHODS: Fifteen patients with nocturnal asthma were studied in a random cross-over design. The esophagus and stomach of the subjects were distended with a balloon. The effect of the distention on the airways was measured by taking forced expiratory volume one second (FEV1), forced vital capacity (FVC) and bronchial hyper-responsiveness (BHR). RESULTS: Distention of stomach caused significant reduction in FEV1 on FEV1/FVC ratio but similar distention of esophagus did not. Histamine PD20 was decreased by 0.43 (SEM 0.28) doubling dose with gastric distention. However, with oesophageal distention no significant change was observed in PD20. CONCLUSION: It can be concluded that gastric distention leads to broncho-constriction as measured by FEV1, FEV1/FVC ratio along with increase in BHR probably by inducing airway inflammation. Therefore asthmatic patients should be advised to avoid large meals.