Comparison of Esophageal Dysmotility and Reflux Burden in Patients with Different Metabolic Obesity Phenotypes Based on High-Resolution Impedance Manometry and 24-h Impedance-pH.

Introduction: The relationship between the metabolically healthy obesity (MHO) phenotype and the occurrence of gastroesophageal reflux disease (GERD) and inefficient esophageal motility (IEM) is still unclear. Thus, we assessed the association between different metabolic obesity phenotypes and GERD and IEM using empirical data.

Methods: We collected clinical and test data of 712 patients, including 24-h multichannel intraluminal impedance-pH (24-h MII-pH) monitoring, high-resolution manometry (HRM), and endoscopy. We divided 567 individuals into four categories according to their metabolic obesity phenotype: metabolically unhealthy non-obesity (MUNO), metabolically unhealthy obesity (MUO), metabolically healthy non-obesity (MHNO), and MHO. We compared differences in the 24-h MII-pH monitoring, HRM, and endoscopy findings among the four metabolic obesity phenotypes.

Results: Patients with the MUNO, MHO, or MUO phenotype showed a greater risk of IEM and GERD (pathologic acid exposure time [AET] >6%) compared with patients with the MHNO phenotype. Regarding the HRM results, patients with the MHNO or MUNO phenotype had a lower integrated relaxation pressure, esophageal sphincter pressure, and esophagogastric junction contractile integral, and more ineffective swallows than patients with the MHO or MUO phenotype (p < 0.05). In terms of 24-h MII-pH, patients with the MHO or MUO phenotype had a higher total, upright, and supine AET; a higher total number of reflux episodes (TRs); and a lower mean nocturnal baseline impedance and post-reflux swallow-induced peristaltic wave index compared with those with the MHNO or MUNO phenotype (all p < 0.05). Considering the odds ratio of 19.086 (95% confidence interval 6.170-59.044) for pathologic AET and 3.659 (95% confidence interval 1.647-8.130) for IEM, patients with the MUO phenotype had the greatest risk after adjusting for all confounding variables.

Conclusion: Obesity and metabolic disorders increase the risk of GERD and IEM. Obesity has a greater impact on esophageal dysmotility and pathologic acid exposure than metabolic diseases.