Effects of adjustable gastric banding on altered gut neuropeptide levels in morbidly obese patients.

BACKGROUND: Patients with gastroesophageal reflux disease (GERD) have alterations of gut neuropeptides, such as neurotensin (N) and motilin (M), which are resolved following antireflux surgery. Obesity is associated with GERD. Since the adjustable gastric band prevents gastroesophageal reflux in morbidly obese patients, this study was performed to investigate plasma levels of N and M before and after adjustable gastric banding (AGB).
METHODS: 47 morbidly obese patients were operated laparoscopically using the Swedish AGB. Pre- and postoperatively basal plasma levels of N and M were investigated. Symptoms such as heartburn, regurgitation and dysphagia were documented, and esophageal manometry as well as 24-hour pH-monitoring were performed pre- and postoperatively. 11 non-obese, asymptomatic, age-matched volunteers served as controls.
RESULTS: After a median postoperative follow-up period of 268 days, a significant weight reduction was observed. Preoperatively, 14 patients suffered from reflux symptoms. An insufficient lower esophageal sphincter (LES) was found in 8 patients, and 2 patients had impaired esophageal body motility. Pathologic pH-testing was found in 6 patients. Postoperatively, reflux symptoms were present in 4 patients; LES findings and pH-testing were normalized in all patients. However, there was significant impairment of esophageal peristalsis. Preoperatively, levels of N were significantly decreased and levels of M increased compared with control subjects. Postoperatively, there was a significant increase of N and levels of M were normalized. Alterations in gut neuropeptides did not correlate with reflux symptoms, impaired gastroesophageal motility, age, gender or BMI.
CONCLUSION: Morbid obesity alters gut neuropeptides, which are resolved by AGB. This may be caused by reduction of hypercaloric nutrition postoperatively rather than by improvement of gastroesophageal reflux.