Effect of Biliopancreatic Diversion on Glucose Homeostasis (BPD-Mingrone)

Biliopancreatic diversion (BPD) surgery results in greater resolution of type 2 diabetes than all other bariatric surgical procedures, and it is hypothesized that this procedure has specific beneficial effects on glucose homeostasis beyond weight loss alone. The BPD procedure is performed in more than 150 patients/year by surgeons at the Division of Obesity and Metabolic Disorders, Catholic University of the Sacred Heart, School of Medicine, in Rome, Italy. The purpose of this study is to provide a better understanding of the effect of the BPD bariatric surgical procedure on insulin action and pancreatic beta cell function. It is hypothesized that weight loss achieved with BPD surgery will have greater effects on insulin sensitivity and beta cell function than weight loss induced by Roux-en-Y gastric bypass (RYGB).

In Roux-en-Y Gastric Bypass Surgery a small gastric pouch is created and connected to a segment of jejunum. Bowel continuity is restored by reconnecting the "Roux" limb and the biliopancreatic limb approximately ~75-150 cm distal to the gastrojejunostomy. Therefore, ingested food bypasses most of the stomach, the entire duodenum, and a short segment of the jejunum.

In Biliopancreatic Diversion Surgery a horizontal gastrectomy is conducted leaving a portion of the stomach, which is connected to the small intestine, ~250 cm from the ileocecal valve and the biliopancreatic limb is connected to the ileum, ~50 cm from the ileocecal valve. Digestive secretions from the biliopancreatic limb mix in the common channel, where ingested food is also delivered by the alimentary limb.

Change from baseline in skeletal muscle insulin sensitivity will be assessed using the Hyperinsulinemic-Euglycemic Clamp (HEC) procedure, before and after weight loss induced by either BPD or RYGB surgery

Insulin sensitivity: The HEC procedure will be used to evaluate insulin sensitivity before and after 20% weight loss induced by either BPD or RYGB surgery

Inclusion Criteria: Body Mass Index (BMI) ≥ 35 kg/m² Undergoing either the RYGB or the BPD procedure. Able to provide informed consent to participate in the research study Exclusion Criteria: Weight > 450 pounds Smoke > 7 cigarettes per day Previous malabsorptive or restrictive intestinal surgery Pregnant or breastfeeding Inflammatory intestinal disease Diabetes Unstable dose of medications in the last 4 weeks before the pre-surgery metabolic studies Severe organ dysfunction

Angelini G, Salinari S, Castagneto-Gissey L, Bertuzzi A, Casella-Mariolo J, Ahlin S, Boskoski I, Gaggini M, Raffaelli M, Costamagna G, Casella G, Marini PL, Gastaldelli A, Bornstein S, Mingrone G. Small intestinal metabolism is central to whole-body insulin resistance. Gut. 2021 Jun;70(6):1098-1109. doi: 10.1136/gutjnl-2020-322073. Epub 2020 Sep 29.

Harris LA, Kayser BD, Cefalo C, Marini L, Watrous JD, Ding J, Jain M, McDonald JG, Thompson BM, Fabbrini E, Eagon JC, Patterson BW, Mittendorfer B, Mingrone G, Klein S. Biliopancreatic Diversion Induces Greater Metabolic Improvement Than Roux-en-Y Gastric Bypass. Cell Metab. 2019 Nov 5;30(5):855-864.e3. doi: 10.1016/j.cmet.2019.09.002. Epub 2019 Oct 3.