Ghrelin gastric tissue expression in patients with morbid obesity and type 2 diabetes submitted to laparoscopic sleeve gastrectomy: immunohistochemical and biochemical study.

Introduction: Obesity and type 2 diabetes mellitus (T2DM) are leading causes of morbidity and mortality worldwide. Ghrelin is implicated in the pathophysiology of both disease states. Laparoscopic sleeve gastrectomy is an emerging safe therapeutic technique for patients with morbid obesity. Since the removal of ghrelin-secreting cells by sleeve gastrectomy may be associated with diminished hunger sensation the aim of the study was to: (i) compare body weight and body mass index (BMI) in both obese non-diabetic and obese diabetic patient groups, (ii) determine the ghrelin expression in the resected gastric tissue in both groups, (iii) evaluate relationships between ghrelin cell expression and pre- and post-operative serum ghrelin concentration and glucose levels, and (iv) assess the influence of sleeve gastrectomy on serum glycaemic parameters in this patient population.

Material and methods: Twenty morbidly obese female patients from Saudi Arabia, of whom ten suffered from T2DM participated in the study. All subjects underwent laparoscopic sleeve gastrectomy. The removed fundus, body and antrum were biopsied and underwent immunohistochemical staining to detect ghrelin cell expression. Serum samples were assayed for ghrelin concentration and indicators of glycaemic status at the baseline and three months after sleeve gastrectomy.

Results: BMI (p < 0.05) and body weight (p < 0.001) were significantly lower in non-diabetic obese patients compared with diabetic patients before and 3 months after the surgery. Also, pre-operative serum ghrelin level was higher in non-diabetic patients compared with diabetic patients group, and postoperative plasma ghrelin level was reduced in diabetic patients (p < 0.001) compared with non-diabetic patients. Gastric fundic mucosa of the diabetic patients exhibited lower number of ghrelin-positive cells (p < 0.05) compared with non-diabetic patients. There were significant negative correlations between pre- and post-operative ghrelin serum level and blood glucose (r = -0.736, p = 0.0002 and r = -0.656, p = 0.0007, respectively) in all patient populations.

Conclusions: The results of this study suggest that the diabetic status of obese female patients may affect the incidence of ghrelin cells in three major stomach's regions and this novel observation warrants further studies.