Background & aims: The aim of the current study was to analyze the relationship between obesity and the morphology of the esophagogastric junction (EGJ) pressure segment using high-resolution manometry.
Methods: Two hundred eighty-five patients (108 men, aged 18-87) were studied. A solid-state manometric assembly with 36 circumferential sensors spaced 1 cm apart was placed transnasally, and simultaneous intra-esophageal and intragastric pressures were measured over 6-8 respiratory cycles. Separation of the lower esophageal sphincter (LES) and crural diaphragm was quantified by measuring the distance between the two EGJ elements during inspiration. The association between anthropometric variables and pressure values were examined using univariate and multivariate analysis.
Results: There was a significant correlation of body mass index (BMI) and waist circumference (WC) with intragastric pressure (inspiration, BMI [r = 0.57], WC [r = 0.62] P < .0001; expiration, BMI [r = 0.58], WC [r = 0.64], P < .0001) and gastroesophageal pressure gradient (GEPG) (inspiration, BMI [r = 0.37], WC [r = 0.43], P < .0001; expiration, BMI [r = 0.24], WC [r = 0.26], P < .0001). Multivariate analysis adjusting for age, gender, and patient type did not alter the direction or magnitude of this relationship. In addition, obesity was associated with separation of the EGJ pressure components (BMI, r = 0.17, P < .005; WC, r = 0.21, P < .001).
Conclusions: Obese subjects are more likely to have EGJ disruption (leading to hiatal hernia) and an augmented GEPG providing a perfect scenario for reflux to occur. Whether or not weight loss can reverse these abnormalities is unknown.