[Effect of blood glucose control after small intestine exclusion surgery in Goto-Kakizaki rat with type 2 diabetes mellitus].

OBJECTIVE

To evaluate the effect of diabetic control after small intestine exclusion surgery in Goto-Kakizaki (GK) rat with type 2 diabetes mellitus.

METHODS

GK type 2 diabetic rats underwent duodenal bypass (Group A, n = 8) creating a shortcut for ingested nutrients with bypassing duodenum alone, or duodenal-jejunal bypass (Group B, n = 8), a stomach-preserving RYGB excluding duodenum and proximal jejunum, or duodenum and total jejunum exclusion (Group C, n = 8), or sub-total small intestine exclusion (Group D, n = 8) creating a shortcut for ingested nutrients with bypassing duodenum, jejunum and sub-total ileum. Controls were pair-fed (PF) sham-operated and untreated GK rats (Group SO, n = 8). Rats were observed for 24 weeks after surgery. Fasting blood glucose (FBG) level was determined on a Surestep plus blood glucose meter (Lifescan) at 0, 1, 3, 6, 12, 24 week. Hemoglobin A1c (HbA1c) level was measured at 0, 12, 24 week on VARIANT Hemoglobin A1c Program (Bio-Ray) with high performance liquid chromatography (HPLC) method.

RESULTS

The fasting blood glucose and HbA1c levels significantly decreased after surgery in all the operative groups through the entire follow-up period [Group B (FBG before surgery and 1 week after: (162 +/- 44) mg/dl vs (80 +/- 19) mg/dl; HbAlc before surgery and 12 week after: (8.2 +/- 2.2)% vs (5.1 +/- 1.5)%, P < 0.05 or P < 0.01]; while FBG had no differences before 12 week and significantly increased at 12 week (164 +/- 44) mg/dl and 24 week (180 +/- 42) mg/dl in group SO [preoperative (145 +/- 35) mg/dl, P < 0.01]. As compared with sham-operated rats, all the operative groups showed reduced blood-glucose and HbA1c levels through the entire follow-up period (P < 0.05 or P < 0.01). The FBG and HbA1c levels in Group B significantly decreased versus Group A [24 week (FBG: (82 +/- 21) mg/dl vs (111 +/- 27) mg/dl; HbA1c: (3.9 +/- 0.9)% vs (5.4 +/- 1.2)%, P < 0.05], indicating that duodenal-jejunal bypass had markedly a better effect of diabetic control. But Groups B, C and D were similar to one another (P > 0.05), suggesting that a potential role of proximal gut in the pathogenesis of disease.

CONCLUSION

In spontaneous type 2 diabetes mellitus rats, all the small intestinal exclusion including proximal gut are effective in glucose control. In terms of intestinal nutrient absorption, duodenal-jejunal bypass may be an ideal surgery for clinical diabetic control. These findings suggest a potential role of proximal intestine in pathogenesis of type 2 diabetes mellitus.