Duodenal-Jejunal Bypass Surgery Enhances Glucose Tolerance and Beta-Cell Function in Western Diet Obese Rats

The aim of this study was to investigate the effect of the duodenal-jejunal bypass (DJB) on glucose homeostasis and islet insulin secretion in Western diet (WD) obese rats. Male Wistar rats received a standard rodent chow diet (CTL group) or WD ad libitum. After 32 weeks of diet, WD rats were submitted to duodenal-jejunal bypass (WD DJB) or sham (WD S-DJB) operation. Intraperitoneal (ip) glucose tolerance test was performed 1 week after surgery. Body weight, fat pad depots, glycemia, insulinemia, HOMA-IR, and glucose-induced insulin secretion were evaluated 1 month after surgery. Body weight and fat pads of the WD group were higher than those of the CTL group. Sham and DJB surgeries did not alter these parameters. WD and WD S-DJB rats were glucose intolerant, insulin resistant, and hyperinsulinemic. WD DJB rats showed similar glucose tolerance, insulin sensitivity, and plasma insulin levels to those of CTL rats. WD rats presented higher fat and glycogen contents in the liver. DJB surgery normalized fat and glycogen stores in the liver of the WD DJB group. Insulin release at 11.1-mM glucose, in isolated islets from WD and WD S-DJB rats, was higher than from islets of CTL rats. In contrast, DJB surgery improves the beta-cell secretory capacity with increased glucose-induced secretion at 5.6-, 11.1-, and 22.2-mM glucose in WD DJB islets, compared with CTL islets. DJB surgery improves glucose homeostasis and enhances beta-cell glucose responsiveness in rats submitted to the WD diet without any modification in adiposity.