Context: Patients with gastric or esophageal surgery and transection of the vagus nerve may suffer from appetite and weight loss but without dysphagia or mechanical obstruction to eating. The gastric hormone ghrelin stimulates food intake and GH release in rodents and man. However, rodents with vagotomy are not sensitive to the feeding effects of ghrelin.
Objective: The objective of the study was to determine whether humans with vagotomy are sensitive to ghrelin.
Study design: The design was a double-blind, randomized, placebo-controlled trial.
Setting: This was a hospital-based study.
Patients: Six men and one woman who all had a previous complete truncal vagotomy with lower esophageal or gastric surgery entered and completed the study.
Intervention: Each patient received 120-min infusions of saline, 1 pmol/kg.min ghrelin, and 5 pmol/kg.min ghrelin on 3 separate days. After 90 min, a buffet meal was served.
Main outcome measure: Energy intake at the buffet meal was measured.
Results: Ghrelin-stimulated GH release in a dose-dependent manner was measured, confirming bioactivity. However, no change in energy intake was observed with either dose of ghrelin [energy intake (kilojoules): saline 2805 +/- 812; ghrelin 1 pmol/kg.min, 2486 +/- 767; ghrelin 5 pmol/kg.min, 2382 +/- 543; P = not significant].
Conclusions: Ghrelin is unlikely to be an effective appetite-stimulatory treatment for patients with vagotomy and esophageal or gastric surgery. Our results suggest that an intact vagus nerve may be required for exogenous ghrelin to increase appetite and food intake in man.