Proton pump inhibitor therapy may alter the sensory motor characteristics of pharyngoesophageal motility in infants with suspected GERD

Background: Acid reflux index (ARI) is a biomarker for gastroesophageal reflux disease (GERD). The effects of short-term proton pump inhibitor (PPI) therapy on pharyngoesophageal motility and clearance mechanisms in infants remain unknown. We hypothesized that pharyngoesophageal reflexes and response to PPI are distinct between infants with 3%-7% and >7% ARI.Methods: Secondary analysis was performed from a subset of infants who participated in a randomized controlled trial (NCT: 02486263). Infants (N = 36, 29.9 +/- 4.3 weeks gestation) underwent 4 weeks of PPI therapy, 1 week of washout, and longitudinal testing to assess: (a) clinical outcomes; (b) pH-impedance and symptom metrics including ARI, distal baseline impedance, clearance time, refluxate height, symptoms, I-GERQ-R scores, symptom association probability; (c) pharyngoesophageal motility reflexes and sensory motor characteristics. Comparisons were performed between infants with 3%-7% versus >7% ARI.Key Results: From the 36 hospitalized infants treated: Pharyngoesophageal reflex latencies were prolonged (p > 0.05) and duration in ARI 3%-7% group only (p = 0.01); GER frequency, proximal ascent and clearance increased (ARI 3%-7%); weight gain velocity, oral feeding success, and fine motor score decreased while length of hospital stays increased in the ARI >7% group despite the decrease in symptoms and I-GERQ-R scores.Conclusions & Inferences: Distinct changes in pharyngoesophageal sensory motor aspects of motility and reflex mechanisms exist after using PPI therapy in infants. Contributory factors may include the effects of maturation and aerodigestive comorbidities (GERD and BPD). Controlled studies incorporating placebo are needed to delineate the effects of PPI on causal and adaptive GERD mechanisms in infants with aerodigestive and feeding-related comorbidities.