Obese patients have stronger peristalsis and increased acid exposure in the esophagus

Obesity is a risk factor for GERD and a potential modulator of esophageal motility.

To assess whether obese patients differ from non-obese patients in terms of esophageal motility and reflux.

Patients (n = 332) were categorized in GERD and controls after clinical assessment, esophageal manometry, and pH monitoring. Non-obese (BMI 16-29.9) and obese (BMI 30-68) were compared in regard of distal esophageal amplitude (DEA), LES pressure (LESP), manometric diagnosis, and esophageal acid exposure (EAE).

Obese showed higher DEA in both controls (122 ± 53 vs. 97 ± 36 mmHg, p = 0.041) and GERD patients (109 ± 38 vs. 94 ± 46 mmHg, p < 0.001), higher LESP in GERD patients (20.5 ± 10.6 vs. 18.2 ± 10.6 mmHg, p = 0.049), higher frequency of nutcracker esophagus in controls (30 vs. 0%, p = 0.001), lower frequency of ineffective motility in GERD patients (6 vs. 20%, p = 0.001), and higher EAE in both controls [total EAE: 1.6% (0.7-5.1) vs. 0.9% (0.2-2.4), p = 0.027] and GERD patients [upright EAE: 6.5% (3.8-11.1) vs. 5.2% (1.5-10.6), p = 0.048]. Multiple linear regression showed that BMI was associated either with EAE (p < 0.001), DEA (p = 0.006), or LESP (in men, p = 0.007).

Obese patients differed from non-obese in terms of esophageal motility and reflux, regardless of the presence of GERD. Obese patients showed stronger peristalsis and increased acid exposure in the esophagus.