Serum obestatin/ghrelin ratio is altered in patients after distal gastrectomy

Background/Aims: Ghrelin is a peptide hormone produced mainly in the stomach, and obestatin is derived by proteolytic cleavage of the ghrelin prepro-hormone. The aim of this study was to determine the postoperative serial changes in these hormones and whether hyperplasia of ghrelin-expressing cells occurs in the remnant stomach. Methods: We prospectively analyzed serial serum samples of 45 early gastric cancer patients and remnant stomach samples of 24 patients. Result: The serum obestatin level on day 2 was lower than that on day 0, and it subsequently returned to the level observed on day 0. In contrast, the serum ghrelin level was lower on days 120 and 210 than on day 0. Eventually, the obestatin/ghrelin ratio was significantly high on day 210 (p = 0.0003). Moreover, we did not observe an increase in the number of ghrelin-expressing cells. The number of ghrelin-expressing cells correlated with the serum ghrelin level. Conclusion: The serum level of obestatin and ghrelin exhibits a different time course in patients who have undergone gastrectomy, and there was no ghrelin-expressing cell hyperplasia in the remnant stomach despite the decrease in serum ghrelin.