['Roux-en-Y gastric bypass (RYGB) ameliorates type 2 diabetes (T2DM) and obesity through alteration in gastrointestinal (GI) hormones.', 'The objective of this study was to investigate the effect of RYGB on GI hormones and cardiometabolic parameters in Zucker diabetic fatty (ZDF) rodents.', 'Winthrop University Hospital, Research and Academic Center', 'Animals were divided into 3 groups, pair-fed (n = 4), ad lib (n = 4), and RYGB (n = 5). This study was carried out for 4 weeks and all related parameters were measured pre- and postsurgery in fasted obese diabetic Zucker rodents.', 'Postoperatively, RYGB significantly decreased fasting blood glucose by 32% compared with ad lib. Plasma insulin and leptin levels were also found to be significantly decreased, by 66% and 38%, respectively, after surgery. Moreover, both glucose-dependent insulinotropic polypeptide (GIP) and peptide tyrosine-tyrosine (PYY) were significantly increased after RYGB-by 300% and 51%, respectively. Glucagon-like peptide-1 (GLP-1) levels were also increased, but the increase was not statistically significant. Total cholesterol levels of the RYGB group remained unchanged for 4 weeks. However, total cholesterol in the ad lib and pair-fed groups increased by 25% and 34%, respectively, compared with initial levels. The cholesterol/high-density lipoprotein (HDL) ratio was decreased in the RYGB group by 14% and 30% compared with the ad lib and pair-fed group, respectively. The RYGB group had a significant decrease in aortic wall thickness of 25% compared with the ad lib and pair-fed groups. Similarly, the RYGB group had a 20-unit (mm Hg) decrease in systolic blood pressure compared with the presurgical value.'] Does roux-en-Y gastric bypass attenuate the progression of cardiometabolic complications in obese diabetic rats via alteration in gastrointestinal hormones?