Endoscopy-Guided Evaluation of Duodenal Mucosal Permeability in Functional Dyspepsia

OBJECTIVES The pathophysiology of functional dyspepsia (FD) is not fully understood. Impaired duodenal mucosal integrity characterized by increased mucosal permeability and/or low-grade inflammation was reported as potentially important etiologies. We aimed to determine the utility of a recently developed simple catheterization method to measure mucosal admittance (MA), the inverse of mucosal impedance, for evaluation of duodenal mucosal permeability in patients with FD. METHODS We conducted two prospective studies. In the first study, duodenal MA of 23 subjects was determined by catheterization during upper endoscopy, and transepithelial electrical resistance (TEER) of duodenal biopsy samples in Ussing chambers was measured to assess the correlation between MA and TEER. In the second study, duodenal MA of 21 patients with FD fulfilling the Rome III criteria was compared with that of 23 healthy subjects. RESULTS The mean MA and TEER values were 367.5±134.7 and 24.5±3.7 Ω cm2, respectively. There was a significant negative correlation between MA and TEER (r=-0.67, P=0.0004, Pearson's correlation coefficient). The mean MA in patients with FD was significantly higher than that in healthy subjects (455.7±137.3 vs. 352.1±66.9, P=0.002, unpaired t-test). No procedure-related complications were present. CONCLUSIONS We demonstrated the presence of increased duodenal mucosal permeability in patients with FD by MA measurement using a simple catheterization method during upper endoscopy.