Clinical significance of ghrelin expression in the gastric mucosa of morbidly obese patients

Background: The concentration of ghrelin, which can affect body weight by influencing appetite, is thought to decrease after sleeve gastrectomy. However, no detailed investigations have examined ghrelin expression in the stomach. The purpose of the present study was to assess localized ghrelin expression and its clinical significance in obese patients. Methods: A total of 52 obese patients who underwent sleeve gastrectomy with or without duodenojejunal bypass were enrolled in the study. The number of ghrelin-positive cells (GPCs) was counted using immunohistochemistry of the gastric mucosa at the fundus. The obese patients were compared with 14 nonobese patients treated for gastric cancer. Ghrelin mRNA expression was also measured in 22 obese patients using a quantitative reverse transcription polymerase chain reaction. Results: The number of GPCs was significantly higher in obese patients than in nonobese controls (33.2 ± 18.3 vs. 14.1 ± 6.1; p < 0.001) and correlated with ghrelin mRNA expression. The obese patients were divided into two groups with high and low ghrelin levels based on the number of GPCs. The percent excess body weight loss was significantly greater in the high-ghrelin group, without differences in the patient backgrounds between the two groups (p = 0.015). Conclusions: The number of GPCs was higher in obese patients than in nonobese patients and varied individually regardless of body weight. These results suggest that ghrelin expression in gastric mucosa might be a prognostic factor after surgery.