The Effects of Antral Preservation and Antral Resection on Body Composition, Glycemic Control and Bone Mineral Density Following Vertical Sleeve Gastrectomy in C57BL/6J Mice with Obesity and Type 2 Diabetes

Abstract

Purpose: Sleeve gastrectomy (SG) is the most currently popular operation for obesity and related metabolic disorders. The aim of this study was to compare the effect of antrum preservation SG (AP-SG) and antrum resection SG (AR-SG) on the body composition, glycemic control and bone mineral density (BMD) in mice.

Methods: Sham, AP-SG and AR-SG operation were performed on obese and T2D C57BL/6J mice (8 in each group). Body weight, food intake, and fasting glucose (FG) levels were measured at the 0, 2, 4, 6 and 8 weeks post-operatively. Oral glucose tolerance test (OGTT) was performed preoperatively and at the eighth postoperative week. The body fat content and total body BMD were evaluated by dual-energy x-ray absorptiometry. After being euthanized, the femurs were harvested and analyzed by micro-CT.

Results: The improvements in body weight, food intake, FG, glycemic control and body fat were statistically significant following AP-SG and AR-SG. Both AP-SG and AR-SG groups decreased total body BMD and regional BMD in the distal femur compared to the sham group. No significant difference of FG was observed in AP-SG and AR-SG group postoperatively, but AR-SG showed significantly superior OGTT glucose AUC than AP-SG. Except for a lower BMD, AR-SG achieved superior outcomes in body fat and glycemic control than AP-SG.

Conclusion: Antrum resection SG shows a lower percentage of body fat and better glycemic control than antrum preservation SG. However, antrum resection SG has a higher risk of having a lower bone mass. Further human clinical trials are needed to confirm this finding.

Keywords: antrum preservation; antrum resection; body fat; bone mineral density; sleeve gastrectomy.

Figure 1

Sleeve gastrectomy (SG) alleviates obesity and glucose metabolic disorders in obese and T2D model. (A) Illustration of sham, antrum preservation SG (AP-SG) and antrum resection SG (AR-SG) operation. The resection line started 1 cm from the pyloric ring (yellow arrow). The resection line started as close as possible near the gastroduodenal junction (green arrow). D = duodenum; A = antrum; S = stomach. (B) Eight weeks after operation, representative appearances of mice in sham, AP-SG and AR-SG group are recorded. Illustrates changes in body weight (C), food intake (D), fasting glucose level (E) after operation. Oral glucose tolerance test (OGTT) results preoperative (F) and postoperatively (G), and area under the curve (AUC) for glucose level (H) are presented. Data (n = 8) are shown as mean ± SD. *Significant AP-SG compared with sham (P < 0.05). ^{^}Significant AR-SG compared with sham (P < 0.05). ^#Significant AR-SG compared with AP-SG. ^aP< 0.05.

Figure 2

Antrum resection sleeve gastrectomy (AR-SG) induces significant body fat reduction than antrum preservation sleeve gastrectomy (AP-SG) in vivo. (A and B) Body fat content after AP-SG and AR-SG are measured by dual-energy X-ray absorptiometry. (C) Visceral adipose tissue after 8 weeks post-operation. (D) Hematoxylin and eosin images of visceral adipose tissue are visualized using an optical microscope. Scale bars: 100 μm. (E) Diameter of adipocytes of visceral adipose tissue in sham, AP-SG and AR-SG groups. *Significant AP-SG compared with sham (P < 0.05). ^{^}Significant AR-SG compared with sham (P < 0.05). ^#Significant AR-SG compared with AP-SG.

Figure 3

Antrum resection sleeve gastrectomy (AR-SG) causes significant bone mass reduction than antrum preservation sleeve gastrectomy (AP-SG). (A and B) Total body bone mineral density (BMD) after sham, AP-SG and AR-SG are measured by dual-energy X-ray absorptiometry. (C) Micro-computed tomography reconstruction images of cancellous bone in the distal femur. (D) Mean/density, (E) Bone volume (BV), and (F) Bone volume/tissue volume (BV/TV) in sham, AP-SG and AR-SG groups. *Significant AP-SG compared with sham (P < 0.05). ^{^}Significant AR-SG compared with sham (P < 0.05). ^#Significant AR-SG compared with AP-SG.