Prospective study of gut hormone and metabolic changes after adjustable gastric banding and Roux-en-Y gastric bypass

J. Korner, W. Inabnet, G. Febres, I. M. Conwell, D. J. McMahon, R. Salas, C. Taveras, B. Schrope, M. Bessler

Research output: Contribution to journalArticlepeer-review

289 Scopus citations


Objective: The objective of this study was to quantify hormones that regulate energy and glucose homeostasis to establish possible mechanisms for the greater efficacy of Roux-en-Y gastric bypass (RYGB) compared with laparoscopic adjustable gastric banding (LAGB) in achieving weight loss and improved insulin sensitivity.Design:Longitudinal study of patients undergoing LAGB (n15) and RYGB (n28) who were studied before surgery and at 2, 12, 26 and 52 weeks afterwards.Measurements:Fasting blood samples were drawn at each visit. Postprandial blood samples were also obtained before surgery and at 26 and 52 weeks. Samples were assayed for peptide YY (PYY), ghrelin, glucagon-like peptide-1 (GLP-1), glucose, insulin, leptin, thyrotropic hormone, free T 4 and free T 3.Results:At 1 year there was greater weight loss in RYGB compared with LAGB patients (30 vs 15%), but final body mass index was similar (34 vs 33 kg m 2). At week 52, area under the curve (AUC) for PYY in RYGB subjects was greater than LAGB (P0.01). GLP-1 levels at 30 min after meal were threefold greater after RYGB compared with LAGB (P0.001). Conversely, ghrelin AUC increased after LAGB at week 52 (P0.05) but tended to decrease after RYGB. Fasting glucose, insulin, and leptin and homeostasis model of assessment (HOMA-IR) decreased in both groups over time but were significantly lower at week 52 after RYGB compared with LAGB. The change in leptin correlated significantly with weight loss in LAGB (r0.86) and RYGB (r0.77), however, HOMA-IR correlated significantly with weight loss only in LAGB (r0.78), and not RYGB (r0.15). There was a significant decrease in free T 3 (P0.01) after RYGB.Conclusions:Differences in levels of gut hormones may play a role in promoting greater weight loss and insulin sensitivity after RYGB compared with LAGB, however, weight loss may be limited by decreases in free T 3 and leptin.

Original languageEnglish
Pages (from-to)786-795
Number of pages10
JournalInternational Journal of Obesity
Issue number7
StatePublished - Jul 2009

Bibliographical note

Funding Information:
J Korner has received lecture fees from Merck and is on the Scientific Advisory Board of Nutrisystem. M Bessler has received lecture fees from Ethicon and Inamed. W Inabnet has received consulting fees from the Surgical Review Corporation and research support from Covidien.

Funding Information:
We thank the participants in this study. This work was supported by NIH grants DK072011 (to JK) and RR00645 (to the General Clinical Research Center).


  • Bariatric surgery
  • GLP-1
  • Ghrelin
  • Insulin secretion
  • Leptin
  • PYY

ASJC Scopus subject areas

  • Medicine (miscellaneous)
  • Endocrinology, Diabetes and Metabolism
  • Nutrition and Dietetics


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