FeNO may serve as a noninvasive screening tool for gastroesophageal reflux disease in children under 5 years: a retrospective study

Objective To investigate the correlation between fractional exhaled nitric oxide (FeNO) measurement and pediatric gastroesophageal reflux disease (GERD), explore potential non-invasive screening indicators for pediatric GERD. Methods A retrospective cohort of 159 children with suspected GERD was enrolled from the Department of Pediatrics, Maternal and Child Health Hospital of Hubei Province between April 2017 and August 2025. Data on 24 h ph and multiple intraluminal impedance monitoring and FeNO were systematically collected and analyzed. Results Among 159 children, 32 (20.1%) were diagnosed with GERD. In the 101 children under 5 years, 23 (22.8%) were GERD-positive. The median FeNO in the GERD-positive group was significantly higher than that in the GERD-negative group (18.00 vs. 10.00 ppb, P < 0.001). Spearman analysis revealed that FeNO was significantly correlated with the number of reflux cycles ( P = 0.012) and pH reflux cycles ( P = 0.010). ROC analysis for FeNO predicting GERD yielded an AUC of 0.751 ( P = 0.000), with an optimal cutoff of 17.5 ppb, a sensitivity of 52.2%, and a specificity of 87.2%. Multivariate logistic regression further confirmed FeNO as an independent risk factor for GERD in children under 5 years. However, in the 58 children aged ≥5 years, no significant difference in GERD-positive rate was observed between the FeNO 50 -positive and FeNO 50 -negative groups ( P = 1.00). Conclusions Elevated FeNO is independently associated with GERD in children under 5 years, showing moderate diagnostic value as a potential non-invasive screening tool, but not in those aged ≥5 years.