OBJECTIVETo compare the effects of Roux-en-Y gastric bypass (RYGBP)procedures preserving different gastric volume on blood glucose of rats with non-obese type 2 diabetes.

METHODSA total of 36 Goto-Kakizaki rats randomly underwent one of the following procedures: gastric bypass with different types of anastomosis including the Roux-en-Y of total stomach excision(n=12), the Roux-en-Y of partial stomach excision(n=12) and the Roux-en-Y of stomach preservation(n=12). Rats were observed for 24 weeks after surgery. Body weight, food intake and fasting blood glucose level were tested at 0(preoperative), 1, 3, 6, 12, 24 weeks. Hemoglobin A1c(HbA1c) level was measured at 0, 12, 24 weeks and glucose tolerance test (OGTT) was performed in conscious rats before (baseline) and then 30, 60, 120, and 180 minutes. Change of blood glucose over time was depicted. Area under curve(AUC) of glucose tolerance were calculated.

RESULTSCompared with preoperative levels, the weight and food intake of all the rats were significantly decreased at 1 week after surgery(P<0.01). At 3 weeks after operation, the weight and food intake were significantly increased compared with 1 week after operation in the Roux-en-Y of partial stomach excision and the Roux-en-Y of stomach retention(P<0.01). In the Roux-en-Y of total stomach excision, the weight and food intake were significantly lower compared with other two groups(P<0.05). At 24 weeks after operation, the levels of fasting blood glucose were (7.3 ± 1.5), (7.5 ± 2.0) and (8.3 ± 1.3) mmol/L, which were lower than the preoperative levels [(13.2 ± 1.6), (13.6 ± 2.5) and (12.9 ± 2.0) mmol/L, P<0.01] in the three groups. There were no significant differences among the three groups(P>0.05). At 24 weeks after operation, the HbA1c levels were(6.3 ± 1.3)%, (6.4 ± 2.0)% and (7.0 ± 1.3)%, which were lower than the preoperative level[(10.2 ± 2.6)%, (9.6 ± 2.5) and (9.9 ± 2.0)%, P<0.01]. There were no significant differences among the three groups(P>0.05). The trend of the glucose tolerance test and AUC were similar in the three groups after operation.

CONCLUSIONRoux-en-Y gastric bypass in non-obese diabetic rats is effective in terms of glucose control and the efficacy of gastric bypass has no obvious association with the stomach volume.