Microvascular Outcomes in Patients With Diabetes After Bariatric Surgery

High-throughput mediation analysis of human proteome and metabolome identifies mediators of post-bariatric surgical diabetes control

To improve the power of mediation in high-throughput studies, here we introduce High-throughput mediation analysis (Hitman), which accounts for direction of mediation and applies empirical Bayesian linear modeling. We apply Hitman in a retrospective, exploratory analysis of the SLIMM-T2D clinical trial in which participants with type 2 diabetes were randomized to Roux-en-Y gastric bypass (RYGB) or nonsurgical diabetes/weight management, and fasting plasma proteome and metabolome were assayed up to 3 years. RYGB caused greater improvement in HbA1c, which was mediated by growth hormone receptor (GHR). GHR’s mediation is more significant than clinical mediators, including BMI. GHR decreases at 3 months postoperatively alongside increased insulin-like growth factor binding proteins IGFBP1/BP2; plasma GH increased at 1 year. Experimental validation indicates (1) hepatic GHR expression decreases in post-bariatric rats; (2) GHR knockdown in primary hepatocytes decreases gluconeogenic gene expression and glucose production. Thus, RYGB may induce resistance to diabetogenic effects of GH signaling.

Trial Registration: Clinicaltrials.gov NCT01073020.

Factors underlying the effects of gastric bypass surgery on glucose homeostasis are incompletely understood. Here the authors developed and applied high-throughput mediation analysis to identify proteome/metabolome mediators of improved glucose homeostasis after to gastric bypass surgery, and report that improved glycemia was mediated by the growth hormone receptor.

ASMBS position statement on the rationale for performance of upper gastrointestinal endoscopy before and after metabolic and bariatric surgery

The following position statement is issued by the American Society for Metabolic and Bariatric Surgery in response to inquiries made to the Society by patients, physicians, society members, hospitals, health insurance payors, the media, and others regarding the need and possible strategies for screening endoscopic examination before metabolic and bariatric surgery (MBS), as well as the rationale, indications, and strategies for postoperative surveillance for mucosal abnormalities, including gastroesophageal reflux disease and associated esophageal mucosal injuries (erosive esophagitis and Barrett's esophagus) that may develop in the long term after MBS, specifically for patients undergoing sleeve gastrectomy or Roux-en-Y gastric bypass. The general principles described here may also apply to procedures such as biliopancreatic diversion (BPD) and BPD with duodenal switch (DS); however, the paucity of procedure-specific literature for BPD and DS limits the value of this statement to those procedures. In addition, children with obesity undergoing MBS may have unique considerations and are not specifically addressed in this position statement. This recommendation is based on current clinical knowledge, expert opinion, and published peer-reviewed scientific evidence available at this time. The statement is not intended to be and should not be construed as stating or establishing a local, regional, or national standard of care. The statement will be revised in the future as additional evidence becomes available.