Gastrin Secretion After Bariatric Surgery-Response to a Protein-Rich Mixed Meal Following Roux-En-Y Gastric Bypass and Sleeve Gastrectomy: a Pilot Study in Normoglycemic Women.

BACKGROUND: Recent investigations have linked elevated gastrin levels to the improvement of type 2 diabetes mellitus (T2DM). Roux-en-Y gastric bypass (RYGB) and sleeve gastrectomy (SG) are effective treatments for T2DM, but it is not known if this is related to postoperative alterations of gastrin secretion. METHODS: Twenty women previously operated with RYGB or SG and 13 female controls were enrolled and evaluated for body mass index, lipids, C-peptide, HbA1c, and anti-H. pylori IgG. Glucose, gastrin, insulin, and glucagon-like peptide 1 (GLP-1) concentrations were measured before and 30, 60, 90, and 120 min after ingestion of a protein-rich mixed meal. RESULTS: Six participants primarily selected were excluded due to usage of proton pump inhibitors, positive H.pylori IgG, or history of T2DM, yielding the following groups: RYGB (n = 9), SG (n = 8), and controls (n = 10). There were no differences in age, body mass index, HbA1c, or C-peptide levels between groups. RYGB had significantly lower area under the curve (AUC) for glucose during the test compared to controls (p = 0.013). RYGB showed lower serum gastrin levels compared to SG and controls (p < 0.05 for all). There was a non-significant increased gastrin release in SG compared to controls (p = 0.091). For SG and controls, there was a negative correlation between glucose and gastrin response (p = 0.0043). CONCLUSION: Gastrin secretion is diminished after RYGB. Hypergastrinemia was not present after SG, but a tendency of enhanced gastrin secretion was observed. These findings require further investigation in prospective studies.

Sleeve gastrectomy, but not duodenojejunostomy, preserves total beta-cell mass in Goto-Kakizaki rats evaluated by three-dimensional optical projection tomography.

BACKGROUND: In type 2 diabetes mellitus, there is a progressive loss of beta-cell mass. Bariatric surgery has in recent investigations showed promising results in terms of diabetes remission, but little is established regarding the effect of surgery on the survival or regeneration of pancreatic beta-cells. In this study, we aim to explore how bariatric surgery with its subsequent hormonal alterations affects the islets of Langerhans. METHODS: Twenty-four Goto-Kakizaki rats were operated with duodenojejunostomy (DJ), sleeve gastrectomy (SG) or sham operation. From the 38th week after surgery, body weight, fasting blood glucose, glycosylated hemoglobin, mixed meal tolerance with repeated measures of insulin, glucagon-like peptide 1, gastrin and total ghrelin were evaluated. Forty-six weeks after surgery, the animals were euthanized and the total beta-cell mass in all animals was examined by three-dimensional volume quantification by optical projection tomography based on the signal from insulin-specific antibody staining. RESULTS: Body weight did not differ between groups (P(g) = 0.37). SG showed lower fasting blood glucose compared to DJ and sham (P(g) = 0.037); HbA1c levels in SG were lower compared to DJ only (p < 0.05). GLP-1 levels were elevated for DJ compared to SG and sham (P(g) = 0.001), whereas gastrin levels were higher in SG compared to the two other groups (P(g) = 0.002). Beta-cell mass was significantly greater in animals operated with SG compared to both DJ and sham (p = 0.036). CONCLUSION: Sleeve gastrectomy is superior to duodenojejunostomy and sham operation when comparing the preservation of beta-cell mass 46 weeks after surgery in Goto-Kakizaki rats. This could be related to both the increased gastrin levels and the long-term improvement in glycemic parameters observed after this procedure.

The effect of duodenojejunostomy and sleeve gastrectomy on type 2 diabetes mellitus and gastrin secretion in Goto-Kakizaki rats.

BACKGROUND: Bariatric surgery is a highly effective treatment of type 2 diabetes in patients with morbid obesity. The weight-loss independent improvement of glycemic control observed after these procedures has led to the discussion whether bariatric surgery can be introduced as treatment for type 2 diabetes in patients with a body mass index < 35 kg/m(2). We have studied the effects of two bariatric procedures on type 2 diabetes and on gastrointestinal hormone secretion in a lean diabetic animal model. METHODS: Male Goto-Kakizaki rats, 17-18 weeks old, were randomized into three groups: duodenojejunostomy (DJ), sleeve gastrectomy (SG), or sham operation. During 36 postoperative weeks we evaluated body weight, fasting blood glucose, glucose tolerance, insulin, HbA1c, glucagon-like peptide 1, cholesterol parameters, triglycerides, total ghrelin, and gastrin. RESULTS: Oral glucose tolerance was significantly improved for both DJ and SG at four weeks after surgery (p < 0.05). At the 34th postoperative week, SG had significantly lower area under the curve during oral glucose tolerance test compared to sham (p = 0.007). SG had significantly lower HbA1c compared to sham at 12 weeks; (mean ± SEM) 4.3 ± 0.1 % versus 5.2 ± 0.3 % (p < 0.05) and compared to both DJ and sham 34 weeks after surgery [median (75 %;25 %)] 5.2 (6.0; 4.3) % versus 7.0 (7.5; 6.7) % and 7.3 (7.6; 6.7) % (p = 0.009). Serum gastrin levels were markedly elevated for SG compared to DJ and sham; 188.0 (318.0; 121.0) versus 77.5 (114.0; 58.0) and 68.0 (90.0; 59.5) pmol/L (p = 0.004) at six weeks and 192.0 (587.8; 110.8) versus 65.5 (77.0; 59.0) and 69.5 (113.0; 55.5) (p = 0.001) 36 weeks after surgery. CONCLUSION: Sleeve gastrectomy induces hypergastrinemia, lowers HbA1c, and improves glycemic control in Goto-Kakizaki rats. Sleeve gastrectomy is superior to duodenojejunostomy as treatment of type 2 diabetes mellitus in this animal model.