Comparison of effectiveness and nutritional condition in obese T2DM rats after sleeve gastrectomy-transit bipartition and biliopancreatic diversion with duodenal switch

Objective To compare the weight loss, hypoglycemic effect and nutritional condition of type 2 diabetes mellitus(T2DM) rats with obesity after sleeve gastrectomy-transit bipartition (SG-TB) and biliopancreatic diversion with duodenal switch (BPD-DS). Methods T2DM diabetes rats with obesity were induced through intraperitoneal injection of a low-dose streptozotocin (35 mg/kg) using high-fat diet for one month. Twenty-four successfully modeled rats were randomly divided into three groups (n=8): a SG-TB group, a BPD-DS group and a sham operation (SHAM) group. Before operation and at post-operative 1 to 3 months, their food intake and body weight were measured; the fasting blood glucose (FBG) were measured; and oral glucose tolerance test (OGTT) and insulin resistance test (ITT) were performed. Before operation and post-operative 1 and 3 months, glucagon-like peptide (GLP-1) and insulin were detected; homeostasis model assessment of insulin resistance (HOMA-IR) was calculated; and the contents of serum albumin (ALB), calcium (Ca), ferrum (Fe), and vitamin B₁₂ (VB₁₂) were detected. Results ①There was no statistical difference in each indicators among the SG-TB group, the BPD-DS group and the SHAM group before operation (P>0.05). ②One to three months after surgery, the body weight and food intake of the SG-TB and BPD-DS groups were remarkably lower than those before surgery, and lower than those of the SHAM group at the corresponding time points (P<0.05). Compared with the BPD-DS group, the SG-TB group showed increases in body weight at post-operative 1-3 months, and increases in food intake one month after operation (P<0.05). ③Both the SG-TB and BPD-DS groups showed significantly lower FBG, OGTT AUC and ITT AUC than the SHAM group (P<0.05). But no statistical difference was found between the SG-TB and BPD-DS groups (P>0.05). ④Compared with the SHAM group, remarkable increases in GLP-1 AUC were found in the BPD-DS group one month after operation and in the SG-TB group at post-operative 3 months (P<0.05). The SG-TB group showed lower GLP-1 AUC than the BPD-DS group, without statistical difference (P>0.05). Both the SG-TB and BPD-DS groups showed significantly lower Insulin AUC and HOMA-IR than the SHAM group (P<0.05). The insulin AUC of the SG-TB group was higher than that of BPD-DS groups at post-operative 1 month (P<0.05). ⑤Both the SG-TB and BPD-DS groups showed significantly lower Fe content than the SHAM group at post-operative 1 and 3 months (P<0.05), but no statistical difference was found between the SG-TB and BPD-DS groups (P>0.05). Compared with the SHAM group, the BPD-DS group showed deceases in Ca content at post-operative 1 and 3 month (P<0.05), while the SG-TB group showed deceases in Ca content three months after operation (P<0.05). The SG-TB group presented lower ALB than the SHAM group one month after operation, while the BPD-DS group presented lower ALB than the SB-TB and SHAM groups at post-operative 1 and 3 month (P<0.05). After operation, both the SG-TB and BPD-DS groups showed lower VB₁₂ content than the SHAM group, without statistical differences (P>0.05). Conclusions SG-TB is easy to operate and has similar effect in improving blood glucose as BPD-DS, with a slightly lower risk of malnutrition than BPD-DS.