Single anastomosis duodeno-ileal bypass with sleeve gastrectomy generates sustained improvement of glycemic control compared with sleeve gastrectomy in the diet-induced obese rat model

Abstract

Bariatric surgery has become a recognized and effective procedure for treating obesity and type 2 diabetes (T2D). Our objective was to directly compare the caloric intake-independent effects of sleeve gastrectomy (SG) and single anastomosis duodenoileal bypass with SG (SADI-S) on glucose tolerance in rats with diet-induced obesity (DIO) and to elucidate the differences between bariatric surgery and caloric restriction.A total of 120 adult male Wistar rats with DIO and insulin resistance were randomly assigned to surgical (sham operation, SG, and SADI-S) and dietary (pair-feeding the amount of food eaten by animals undergoing the SG or SADI-S surgeries) interventions. Body weight and food intake were weekly monitored, and 6 weeks after interventions, fasting plasma glucose, oral glucose and insulin tolerance tests, plasma insulin, adiponectin, GIP, GLP-1, and ghrelin levels were determined.The body weight of SADI-S rats was significantly (p < 0.001) lower as compared to the sham-operated, SG, and pair-fed groups. Furthermore, SADI-S rats exhibited decreased whole body fat mass (p < 0.001), lower food efficiency rates (p < 0.001), and increased insulin sensitivity, as well as improved glucose and lipid metabolism compared to that of the SG and pair-fed rats.SADI-S was more effective than SG, or caloric restriction, in improving glycemic control and metabolic profile, with a higher remission of insulin resistance as well as long-term weight loss.

Keywords: Diet-induced obesity; Glucose metabolism; Single anastomosis duodeno-ileal bypass; Sleeve gastrectomy.

Fig. 1

Flow diagram outlining the final experimental design. HFD, high-fat diet; ND, normal diet; PFD, pair-fed; SADI-S, single anastomosis duodeno-ileal bypass with sleeve gastrectomy; SG, sleeve gastrectomy

Fig. 2

The improvement of body weight and adiposity after SADI-S, but not SG, is beyond caloric restriction. A Growth curves of rats 6 weeks after surgical and caloric interventions. Bar graphs illustrate B the total weight loss of the experimental animals and C the total white adipose tissue. Values are the mean ± SEM (n = 15–20/group). Differences were analyzed by one-way ANOVA followed by Bonferroni post hoc tests. ***p < 0.001 vs. sham-operated group; ΔΔΔ p < 0.001 vs. SG group; ^§§§p < 0.001 vs. PFD SADI-S rats. BW, body weight; FER, food efficiency ratio; PFD, pair-fed; SADI-S, single anastomosis duodeno-ileal bypass with sleeve gastrectomy; SG, sleeve gastrectomy; TWL, total weight loss; AT, white adipose tissue

Fig. 3

The beneficial effect of SADI, but not SG, on glycemic control is independent of caloric restriction. A Evolution of glucose after oral glucose tolerance and C intraperitoneal insulin tolerance tests. B Bar graphs show the AUC in the oral glucose tolerance and D intraperitoneal insulin tolerance tests. Values are the mean ± SEM (n = 15–20/group). Differences were analyzed through one-way ANOVA followed by Bonferroni post hoc tests. ***p < 0.001 vs. sham-operated group; ^ΔΔΔp < 0.001 vs. SG group; ^§p < 0.05, ^§§p < 0.01, ^§§§p < 0.001 vs. PFD SADI-S rats. AUC, area under the curve; IPITT, intraperitoneal insulin tolerance test; OGTT, oral glucose tolerance test; PFD, pair-fed; SADI-S, single anastomosis duodeno-ileal bypass with sleeve gastrectomy; SG, sleeve gastrectomy