Equivalent Weight Loss with Marked Metabolic Benefit Observed in a Matched Cohort with and Without Type 2 Diabetes 12 Months Following Gastric Bypass Surgery

Abstract Context: Gastric bypass surgery (GBP) results in rapid weight loss, improvement of type 2 diabetes (T2DM), and increase in incretins levels. Diet-induced weight loss also improves T2DM and may increase incretin levels. Objective: Our objective was to determine whether the magnitude of the change of the incretin levels and effect is greater after GBP compared with a low caloric diet, after equivalent weight loss. Design and Methods: Obese women with T2DM studied before and 1 month after GBP (n = 9), or after a diet-induced equivalent weight loss (n = 10), were included in the study. Patients from both groups were matched for age, body weight, body mass index, diabetes duration and control, and amount of weight loss. Setting: This outpatient study was conducted at the General Clinical Research Center. Main Outcome Measures: Glucose, insulin, proinsulin, glucagon, gastric inhibitory peptide (GIP), and glucagon-like peptide (GLP)-1 levels were measured after 50-g oral glucose. The incretin effect was measured as the difference in insulin levels in response to oral and to an isoglycemic iv glucose load. Results: At baseline, none of the outcome variables (fasting and stimulated values) were different between the GBP and diet groups. Total GLP-1 levels after oral glucose markedly increased six times (peak:17 ± 6 to 112 ± 54 pmol/liter; P < 0.001), and the incretin effect increased five times (9.4 ± 27.5 to 44.8 ± 12.7%; P < 0.001) after GBP, but not after diet. Postprandial glucose levels (P = 0.001) decreased more after GBP. Conclusions: These data suggest that early after GBP, the greater GLP-1 and GIP release and improvement of incretin effect are related not to weight loss but rather to the surgical procedure. This could be responsible for better diabetes outcome after GBP.

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Role of Gut-Related Peptides and Other Hormones in the Amelioration of Type 2 Diabetes after Roux-en-Y Gastric Bypass Surgery

ISRN Endocrinology ◽

10.5402/2012/504756 ◽

2012 ◽

Vol 2012 ◽

pp. 1-13 ◽

Cited By ~ 14

Author(s):

Mirella P. Hage ◽

Bassem Safadi ◽

Ibrahim Salti ◽

Mona Nasrallah

Keyword(s):

Type 2 Diabetes ◽

Weight Loss ◽

Gastric Bypass ◽

Bypass Surgery ◽

Cell Function ◽

Gastric Bypass Surgery ◽

Gastrointestinal Hormones ◽

Gut Peptides

Bariatric surgery is currently the most effective and durable therapy for obesity. Roux-en-Y gastric bypass surgery, the most commonly performed procedure worldwide, causes substantial weight loss and improvement in several comorbidities associated with obesity, especially type 2 diabetes. Several mechanisms are proposed to explain the improvement in glucose metabolism after RYGB surgery: the caloric restriction and weight loss per se, the improvement in insulin resistance and beta cell function, and finally the alterations in the various gastrointestinal hormones and adipokines that have been shown to play an important role in glucose homeostasis. However, the timing, exact changes of these hormones, and the relative importance of these changes in the metabolic improvement postbariatric surgery remain to be further clarified. This paper reviews the various changes post-RYGB in adipokines and gut peptides in subjects with T2D.

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