Correlation of Esophageal Mean Nocturnal Baseline Impedance With Markers of Laryngopharyngeal Reflux

Objectives Mean nocturnal baseline impedance (MNBI) is a measure of the esophageal epithelial barrier function calculated via high‐resolution impedance manometry and can be used as a diagnostic tool and treatment response predictor for gastroesophageal reflux disease (GERD). However, its utility for laryngopharyngeal reflux (LPR) has been minimally studied. We aimed to investigate the relationship of MNBI between patients with suspected LPR, healthy controls, and their 24‐h multichannel intraluminal impedance‐pH (MII‐pH) study results. Methods Retrospective patient series analysis was performed of patients with suspected LPR and healthy controls who underwent 24‐h MII‐pH monitoring. MNBI values were calculated from impedance channels at the level of the hypopharynx, proximal esophagus, and distal esophagus. We compared these MNBI values between the subject groups with secondary analysis on MII‐pH results, reflux symptom index, reflux findings score, DeMeester score, and salivary pepsin levels. Results Twenty‐three patients with suspected LPR and 14 healthy controls were enrolled. Decreased distal esophageal MNBI was found to be significantly decreased in patients with suspected LPR compared with healthy controls ( p < 0.01) and in subjects with positive MII‐pH studies compared to negative MII‐pH studies ( p < 0.01). There were no significant correlations of MNBI at the hypopharynx or proximal esophagus. Conclusion Distal esophageal MNBI has significant correlations with many phenotypic and biological markers of LPR. These findings indicate that MNBI has the potential to be applied to LPR, similar to its emerging use as a diagnostic tool and treatment response predictor for GERD. Level of Evidence 3 Laryngoscope , 133:1927–1932, 2023