Postprandial Metabolism After Bariatric Surgery in Type 2 Diabetes

Summary

Bariatric surgery procedures have now been firmly demonstrated to lead to significant improvement and even, in many cases, complete reversal of abnormal glucose homeostasis in type 2 diabetes (T2D). Various surgery procedures are can be performed to induce weight loss. The most striking anti-diabetic effects are observed with biliopancreatic diversion with duodenal switch (BPD-DS), followed by Roux-in-Y gastric bypass (RYGB) and sleeve gastrectomy (SG). The first two procedures induce both a restriction of energy intake and a low absorption of dietary fatty acids while the latter exclusively targets energy intake restriction. The investigator and others have shown that improvement of T2D occurs within days after BPD-DS or RYGB in the vast majority of patients, prior to any significant weight loss. This very rapid metabolic recovery is explained by a normalization of β-cell function after meal challenges and ameliorated hepatic insulin sensitivity. The investigator and others have shown that these acute anti-diabetic effects are mostly recapitulated by matched caloric restriction, independent of changes in gastrointestinal hormones, showing the importance of gastrointestinal-derived energy fluxes for acute diabetes control. Muscle insulin sensitivity, on the other hand, improves more slowly in association with weight loss, demonstrating the heterogeneous metabolic response of the various organs to BPD-DS. Some preliminary studies also demonstrate a rapid reduction of NEFA levels and production rate upon i.v. administration of lipids during euglycemic hyperinsulinemic clamps. This very rapid improvement in NEFA tolerance strongly suggests that adipose tissue storage of circulating fatty acids also improves very rapidly, prior to any significant weight loss, after BPD-DS. It may also suggest an acceleration of oxidative fatty acid metabolism in organs such as the liver, the heart and/or skeletal muscles. Studies of the rapid metabolic changes after bariatric surgery conducted thus far rapidly improved the understanding of the fundamental pathogenic defects of T2D. However, much remains to be understood about the acute changes in gastrointestinal-derived metabolic fluxes, organ-specific metabolic responses to bariatric surgery and their relationship with the reversal of T2D. Using in vivo methodological approaches, the investigator proposes to investigate the early organ-specific changes in dietary fatty acid metabolism in response to BPD-DS vs. SG and their relation to improved systemic changes in glucose homeostasis, insulin sensitivity and β-cell function in patients with T2D.

Conditions

• Type 2 Diabetes
• Obese

Interventions

PROCEDURE

biliopancreatic diversion with duodenal switch

PROCEDURE

sleeve gastrectomy

OTHER

liquid meal

will be consumed over 30 minutes with \[U-13C\]-palmitate (0.2 g mixed in the liquid meal) and H2-glucose

RADIATION

PET/scan

a dynamic and whole body PET acquisition will be performed on a thoraco-abdominal segment, 150 minutes after an oral administration of 18FTHA

OTHER

[7,7,8,8-2H]-palmitate

i.v. administration of \[7,7,8,8-2H\]-palmitate (in 25% human albumin) from time -60 to 360 min.

DEVICE

indirect calorimetry

will be performed every hour throughout the protocol along with exhaled breath collection

Sponsors & Collaborators

• Laval University

  collaborator OTHER

• Université de Sherbrooke

  lead OTHER

Principal Investigators

• André Carpentier, MD · Université de Sherbrooke

Study Design

Allocation

NON_RANDOMIZED

Purpose

TREATMENT

Masking

NONE

Model

PARALLEL

Eligibility

Min Age

18 Years

Max Age

65 Years

Sex

ALL

Healthy Volunteers

Yes

Timeline & Regulatory

Start

2015-08-31

Primary Completion

2019-12-31

Completion

2019-12-31

Countries

• Canada

Study Locations