Background and aims It has been reported that gastro-oesophageal reflux (GOR) can be induced by exercise, as described in adult subjects; studies in children are lacking. We sought whether the presence of acid in the oesophagus may increase with exercise and its potential relationship with atopy and lung function in children.
Methods We recruited 45 patients (M/F: 30/15) aged 11 ± 2.7 years with reported exercise-induced respiratory symptoms; subjects were asked for frequency of gastrointestinal symptoms. All patients did lung function before and after 24-h gastro-oesophageal (GO) pH monitoring; they also underwent exercise testing (treadmill) before removing GO catheter. GO-pH was also analysed for 6 min intervals before, during and after exercise. The gastro-oesophageal reflux disease (GORD) was defined as a 24-hour reflux index (IR) ≥ 4.5% and/ or symptom index ≥ 50%. Total serum IgE levels were also assessed.
Results GORD was found in 11/45 (24.4%) of our patients; these children had also a higher IR score during exercise than patients without GORD (7.1 ± 18.5 vs 0.5 ± 2.3, p < 0.05). A fall of GO-pH was recorded during exercise, greater in children with GORD as compared with those without (17.2 ± 42.2 vs 0.9 ± 6.4, p = 0.03). The exercise-induced fall in GO-pH was associated with frequent gastrointestinal symptoms and correlated with IgE levels and baseline FEV1% (IgE: r = -0.37, FEV1%: r = -0.31, p < 0.05 for both).
Conclusions Our results suggest that oesophageal acidity increase with exercise, particularly in atopic children with frequent gastrointestinal symptoms and low baseline respiratory function.