Children with Cystic Fibrosis Have Prolonged Chemical Clearance of Acid Reflux Compared to Symptomatic Children Without Cystic Fibrosis

Abstract

Few studies compare gastroesophageal reflux (GER) parameters of cystic fibrosis (CF) children and symptomatic non-CF children. We aimed to compare the impedance-pH (IMP-pH) parameters for these two groups and to test the hypothesis that prolonged acid exposure in CF patients is due to delayed chemical clearance (CC). IMP-pH tracings from 16 CF children (median 8.2 years) and 16 symptomatic non-CF children (median 8.3 years) were analyzed. Software was used to generate IMP-pH reports and parameter data were extracted. IMP-pH was used to calculate the mean CC for each patient. pH studies showed no difference in acid GER (AGER) frequency (p = 0.587); however, mean AGER duration, duration of longest AGER, AGER index, and DeMeester scores were all significantly higher for CF patients. IMP showed no difference in GER frequency [neither acidic (p = 0.918) nor non-acidic (p = 0.277)], but total bolus clearance was more efficient in CF patients (p = 0.049). A larger percentage of total GER reached the proximal esophagus in non-CF children (p = 0.039). Analyses of two-phase AGER episodes showed that these events were more acidic (p = 0.003) and the CC phase was significantly prolonged in the CF cohort (p = 0.001). Compared to symptomatic non-CF children, CF children do not have more frequent reflux. Actually, they have better bolus clearance efficiency following reflux and may even have better control over the number of GER episodes that reach the proximal esophagus. CC of AGER, however, is significantly prolonged in the CF cohort, likely due to hyperacidity of refluxed gastric contents.