Changes in plasma ghrelin concentration immediately after gastrectomy in patients with early gastric cancer

Although the majority of circulating ghrelin originates from the stomach, no prospective study of the proportion of ghrelin derived from the stomach has been reported. Patients with early gastric cancer who underwent gastric resection were divided into three groups according to the extent and site of gastric resection: subtotal gastrectomy group (n = 24), proximal gastrectomy group (n = 4), and total gastrectomy group (n = 12). Patients with advanced gastric cancer who underwent gastrojejunostomy without gastrectomy served as the bypass group (n = 5). Blood samples were collected from all patients preoperatively, at 1 h after gastric resection or gastrojejunostomy, and on postoperative d 1, 3, and 7. The plasma ghrelin level was determined in all samples and expressed as a percentage of the preoperative level. In the bypass group, no significant drop in the ghrelin level was observed at 1 h after gastrojejunostomy, and the ghrelin level remained stable through postoperative d 7. In the subtotal gastrectomy group, the ghrelin concentration reached a nadir of 38.8 +/- 12.9% of preoperative levels at 1 h after gastric resection and then gradually increased to 88.1 +/- 13.2% by postoperative d 7. In the proximal gastrectomy group, the nadir ghrelin level was 24.5 +/- 15.4% at 1 h after gastric resection and was followed by a gradual recovery. However, the recovery rate was slower than that in the subtotal gastrectomy group, with the ghrelin level reaching only 47.6 +/- 18.8% by postoperative d 7 (P < 0.05). In the total gastrectomy group, the nadir ghrelin level was 28.6 +/- 11.1% at 1 h after gastric resection and remained at 30.0 +/- 13.2% until postoperative d 7. These results suggest that compensatory ghrelin production can occur in the remnant stomach after the surgical removal of part of the stomach and that the proximal fundus is more important than the distal antrum and body in terms of the capacity for ghrelin production. The principal site of ghrelin production is clearly the stomach, which contributes 70% of the circulating ghrelin concentration.