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Cited by 338Bariatric Surgery and OutcomesRegulation of Appetite and ObesityMinimally Invasive Surgical Techniques

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

Open access
Korner, J, Inabnet, W, Febres, G, Conwell, I M, McMahon, D J, Salas, R, Taveras, C, Schrope, B +1 more·2009·International Journal of Obesity
DOI 10.1038/ijo.2009.79PMC PMC2710396
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Abstract

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 (n=15) and RYGB (n=28) 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 T4 and free T3.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 (P<0.01). GLP-1 levels at 30 min after meal were threefold greater after RYGB compared with LAGB (P<0.001). Conversely, ghrelin AUC increased after LAGB at week 52 (P<0.05) 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 (r=0.86) and RYGB (r=0.77), however, HOMA-IR correlated significantly with weight loss only in LAGB (r=0.78), and not RYGB (r=0.15). There was a significant decrease in free T3 (P<0.01) 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 T3 and leptin.

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Crossref · 10.1038/ijo.2009.79

Cites

45 of 45 references verified0 citation errors · 0 not checkable

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Claims the paper makes

0 of 27 cited sources checked · 0 supported · 0 flagged

  • Findingown data

    Fasting GLP-1 did not change significantly over time in either group.

    “Fasting levels of GLP-1 did not change significantly over time in either group (Table 1).”
    Quote in the paperNot a substantial claim
  • Findingown data

    Correlation of percent change in free T3 with percent change in leptin at week 52 did not reach statistical significance in LAGB (r=0.46) or RYGB (r=0.38).

    “correlation of the percent change in free T3 with percent change in leptin at wk 52 did not reach statistical significance in LAGB (r = 0.46, P = 0.115) or RYGB (r = 0.38, P =0.101).”
    Quote in the paperNot a substantial claim
  • Findingown data

    At 30 minutes after a meal, GLP-1 levels were about threefold higher after RYGB than after LAGB.

    “GLP-1 levels at 30 min post-meal were three-fold greater after RYGB compared with LAGB (P<0.001).”
    • Also stated in: § GLP-1 · plain
      “In contrast, postprandial GLP-1 levels after RYGB were significantly greater (P < 0.001) compared with 30 minute values before surgery and three-fold higher compared the same time points after LAGB (P < 0.001).”
    Quote in the paperSubstantial claim
  • Findingown data

    Fasting leptin levels did not differ at baseline between LAGB and RYGB.

    “Fasting leptin levels did not differ at baseline between groups (Table 1).”
    Quote in the paperNot a substantial claim
  • Findingown data

    Changes in fasting ghrelin or ghrelin AUC did not correlate with percent weight loss in either group.

    “Changes in fasting ghrelin or AUC did not correlate with percent weight loss in either group.”
    Quote in the paperNot a substantial claim
  • May combine two claims. 23
  • Classified as probably not a substantial claim. 14

  • May combine two claims.

    Findingown data

    Postprandial GLP-1 after RYGB was significantly greater than pre-surgery and threefold higher than after LAGB at the same time points.

    “In contrast, postprandial GLP-1 levels after RYGB were significantly greater (P < 0.001) compared with 30 minute values before surgery and three-fold higher compared the same time points after LAGB (P < 0.001).”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    Postprandial insulin peaked at 30 minutes and did not differ between LAGB and RYGB, but decreased faster in RYGB at 60 minutes at weeks 26 and 52.

    “Postprandial insulin levels peaked at 30 minutes and were not different between LAGB and RYGB, however, there was a more rapid decrease in the RYGB group such that insulin levels at 60 minutes were significantly lower at wk 26 (P = 0.002) and wk 52 (P = 0.016) compared with the same time points in the LAGB subjects (Fig. 3).”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Findingown data

    PYY AUC in RYGB increased at week 26 and further increased at week 52.

    “There was a corresponding 3-fold increase in AUC for PYY in the RYGB group at wk 26 (P < 0.001) and a continued increase in PYY levels such that AUC at wk 52 was significantly greater than at wk 26 (P = 0.025).”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    At 26 and 52 weeks, PYY at 30 minutes after meal was about 3.5-fold greater than pre-surgery and significantly greater than in LAGB.

    “At 26 and 52 wks, PYY levels at 30 minutes were approximately 3.5-fold greater than levels prior to surgery and were significantly greater than in LAGB subjects at the same time points (Fig. 2, P < 0.001).”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    HOMA-IR did not correlate with weight loss in RYGB at week 12 (r=0.21) or week 52 (r=0.15).

    “Significant correlation of HOMA-IR and percent weight loss was not observed in RYGB subjects at week 12 when the range of loss was comparable to LAGB at 1 year (r = 0.21; P = 0.37), or at wk 52 (r = 0.15, P = 0.56)”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Findingown data

    Fasting ghrelin in RYGB showed a downward trend, but the difference at week 52 versus baseline was not statistically significant.

    “Conversely, there was a downward trend in fasting ghrelin levels in RYGB, but the difference in fasting values at wk 52 compared to baseline was not statistically significant (P = 0.422).”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Findingown data

    Fasting PYY increased progressively in RYGB, with week 52 levels significantly greater than baseline.

    “There was a progressive increase in fasting PYY in the RYGB group such that at wk 52 levels were significantly greater than baseline (P = 0.014).”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    Post-meal suppression of ghrelin did not differ significantly from pre-surgery to week 52 in either LAGB or RYGB, and did not differ between groups.

    “The degree of suppression of ghrelin levels post-meal did not differ significantly pre-surgery to wk 52 in either the LAGB (16% ± 3.5 vs 19% ± 3.2) or the RYGB (21% ± 3.4 vs 22% ± 1.8) and did not differ between groups.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Findingown data

    Free T4, free T3, and TSH did not change significantly over time in LAGB.

    “Free T4, free T3 and TSH did not change significantly over time in the LAGB group (Table 2)”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Findingown data

    Leptin decreased significantly at week 2 in RYGB and continued to decrease from week 2 to 12 and week 12 to 26, then stabilized from week 26 to 52.

    “Leptin levels at wk 2 were also significantly decreased in RYGB subjects (P < 0.001). The percent change from baseline after RYGB (Fig. 5) continued to decrease from wk 2 to 12 (P < 0.001) and wk 12 to 26 (P = 0.019), showing stabilization from wk 26 to 52 (P = 0.294).”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Findingown data

    Fasting glucose, insulin, leptin, and HOMA-IR decreased over time in both LAGB and RYGB groups.

    “Fasting glucose, insulin, and leptin, and HOMA-IR decreased in both groups over time”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    Fasting ghrelin in LAGB at week 52 did not increase significantly compared with baseline, but the change in ghrelin was significant (43 ± 12%) and AUC increased.

    “Absolute levels of fasting ghrelin in LAGB subjects at wk 52 did not increase significantly compared with baseline (Table 1, P = 0.073), although the change in ghrelin was significant (43 ± 12%, P = 0.001), as was the increase in AUC (Fig. 2, P = 0.044).”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Findingown data

    Leptin decreased significantly at week 2 in LAGB and did not decrease further despite continued weight loss.

    “There was a significant decrease at wk 2 in LAGB subjects (P < 0.001), but levels did not decrease further despite continued weight loss.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Interpretationcitation

    Inter-individual variation in fasting ghrelin after RYGB may be explained by variable treatment of vagal fibers.

    “It is possible that variable treatment of vagal fibers explains inter-individual variation in fasting ghrelin levels (27).”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [27] Williams DL, Grill HJ, Cummings DE, Kaplan JM . Vagotomy dissociates short- and long-term controls of circulating ghrelin. Endocrinology 2003; 144: 5184–5187. source

      Not checked in the free run.

  • May combine two claims.

    Interpretationown data

    HOMA-IR decreased to a greater extent after RYGB and did not correlate with weight loss, unlike LAGB.

    “HOMA-IR decreased to a greater extent in RYGB subjects and did not correlate with the degree of weight loss as was observed in LAGB subjects.”
    Quote in the paperSubstantial claim
    • Rests on an assumption: The non-randomized LAGB and RYGB groups are comparable enough that between-group differences in outcomes can be attributed to the procedures.

  • May combine two claims.

    Interpretationreasoning

    The increase in fasting ghrelin after LAGB appears to occur over time and is related to weight loss rather than restriction of nutrient flow.

    “The increase in fasting ghrelin after LAGB appears to occur over time indicating that such change is related to weight loss as opposed to restriction of nutrient flow.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Interpretationcitation

    The exaggerated postprandial PYY and GLP-1 response after RYGB is likely secondary to the intervention itself rather than weight loss, possibly due to more rapid delivery of glucose to the distal small intestine.

    “This increase has been reported to occur as early as 2 days after bypass suggesting that the exaggerated response is secondary to the intervention per se and not to weight loss and is likely related to more rapid delivery of glucose to the distal small intestine (15).”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites [15] Chaikomin R, Doran S, Jones KL, Feinle-Bisset C, O'Donovan D, Rayner CK et al. Initially more rapid small intestinal glucose delivery increases plasma insulin, GIP, and GLP-1 but does not improve overall glycemia in healthy subjects. Am J Physiol Endocrinol Metab 2005; 289: E504–E507. source

      Not checked in the free run.

    • Rests on an assumption: The non-randomized LAGB and RYGB groups are comparable enough that between-group differences in outcomes can be attributed to the procedures.

  • May combine two claims.

    Interpretationreasoning

    Some hormone changes after LAGB and RYGB are mostly related to weight loss regardless of procedure, while others are mostly due to the surgical intervention itself.

    “As discussed below, some of these changes were mostly related to weight loss regardless of the type of surgery, yet some were due mostly to the surgical intervention itself”
    Quote in the paperSubstantial claim
    • Rests on an assumption: The non-randomized LAGB and RYGB groups are comparable enough that between-group differences in outcomes can be attributed to the procedures.

  • May combine two claims.

    Study design and conductown data

    The DSL and LINCO PYY assays correlated significantly (r=0.9), but absolute values were lower in the LINCO assay, and a conversion equation was used.

    “There was significant correlation between assays (r = 0.9, P < 0.001), however, absolute values were lower in the LINCO assay. The following equation was found by an ordinary least squares solution to calculate comparable DSL value: −58.3 + 2.8(LINCO value).”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Study design and conductown data

    The PYY assay had a lower limit of detection of 12 pg/ml and coefficients of variation of 10.1% within and 10.3% between assays.

    “The lower limit of detection was 12 pg/ml and the coefficients of variation were 10.1% within and 10.3% between assays.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    GLP-1 functions as an incretin to potentiate glucose-stimulated insulin release.

    “As part of the “enteroinsular axis,” GLP-1 also functions as an incretin to potentiate glucose-stimulated insulin release.”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [7] Vincent RP, Ashrafian H, le Roux CW . Mechanisms of disease: the role of gastrointestinal hormones in appetite and obesity. Nat Clin Pract 2008; 5: 268–277. source

      Not checked in the free run.

  • Classified as probably not a substantial claim.

    Study design and conductnone given

    Subjects with type 2 diabetes at baseline were excluded from analyses of glucose, insulin, and HOMA-IR.

    “Subjects with type 2 diabetes (2 LAGB, 6 RYGB) at baseline were excluded from analyses of glucose, insulin and HOMA-IR.”
    Quote in the paperSubstantial claim

  • Probably not a substantial claim: may not pass S2 (checkable), S3 (load-bearing).

    Study design and conductown data

    More subjects may be required to demonstrate an interaction between free T3 and leptin.

    “It is possible that more subjects would be required to demonstrate an interaction with free T3 and leptin in this setting.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Study design and conductnone given

    Physical activity, eating patterns, environmental and psychological factors were not addressed in this study.

    “Certainly there are variables that play critical roles in weight loss such as physical activity and eating patterns, together with environmental and psychological factors that were not addressed in this study.”
    Quote in the paperNot a substantial claim

  • Classified as probably not a substantial claim.

    Study design and conductreasoning

    As an observational study, the authors can only draw inferences about physiological effects from the hormonal changes.

    “As an observational study we are only able to draw inferences regarding the physiological effects that result from the hormonal changes described”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Premisecitation

    Average weight reduction is approximately 28% after LAGB and 40% after RYGB, and type 2 diabetes remission occurs in 48% and 84% respectively.

    “The average reduction in body weight is approximately 28% after laparoscopic adjustable gastric banding (LAGB) and 40% after Roux-en-Y gastric bypass (RYGB) and metabolic benefits such as remission of type 2 diabetes occurs in 48% and 84% in LAGB and RYGB patients, respectively (3, 4).”
    Quote in the paperNot a substantial claim0 of 2 sources checked
    • cites [3] Sjöström L, Lindroos AK, Peltonen M, Torgerson J, Bouchard C, Carlsson B et al. Lifestyle, diabetes, and cardiovascular risk factors 10 years after bariatric surgery. N Engl J Med 2004; 351: 2683–2693. source

      Not checked in the free run.

    • cites [4] Buchwald H, Avidor Y, Braunwald E, Jensen MD, Pories W, Fahrbach K et al. Bariatric surgery: a systematic review and meta-analysis. JAMA 2004; 292: 1724–1737. source

      Not checked in the free run.

  • May combine two claims.

    Premisecitation

    Previous cross-sectional studies by the authors showed that circulating gut hormone levels differ between LAGB and RYGB patients, with an exaggerated postprandial increase in PYY, GLP-1, and insulin in the RYGB group.

    “In previous cross-sectional studies we have demonstrated that circulating levels of several gut hormones differ in patients who had undergone LAGB compared with RYGB (10, 11). The most striking difference between procedures was an exaggerated postprandial increase in PYY, GLP-1 and insulin concentrations in the RYGB group.”
    Quote in the paperSubstantial claim0 of 2 sources checked
    • cites [10] Korner J, Bessler M, Inabnet W, Taveras C, Holst JJ . Exaggerated GLP-1 and blunted GIP secretion are associated with gastric bypass but not gastric banding. Surg Obes Relat Dis 2007; 3: 597–601. source

      Not checked in the free run.

    • cites [11] Korner J, Inabnet W, Conwell IM, Taveras C, Daud A, Olivero-Rivera L et al. Differential effects of gastric bypass and banding on circulating gut hormone and leptin levels. Obesity 2006; 14: 1553–1561. source

      Not checked in the free run.

  • Classified as probably not a substantial claim.

    Study design and conductown data

    GLP-1 measurements for the entire postprandial period were not obtained due to limited sample volume.

    “Unfortunately, due to the limitation in sample volume we were unable to obtain GLP-1 measurements for the entire postprandial period.”
    Quote in the paperSubstantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Premisecitation

    Ghrelin stimulates appetite, increases food intake and gut motility, and decreases insulin sensitivity.

    “In contrast, ghrelin stimulates appetite, increases food intake and gut motility and decreases insulin sensitivity (8).”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [8] Wiedmer P, Nogueiras R, Broglio F, D'Alessio D, Tschöp MH . Ghrelin, obesity and diabetes. Nat Clin Pract Endocrinol Metab 2007; 3: 705–712. source

      Not checked in the free run.

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Study design and conductnone given

    No adjustment of the critical value was made for the separate tests of different hormones or for HOMA-IR.

    “No adjustment of the critical value of the test statistic was made for the separate tests of different hormones or for HOMA-IR”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    Weight loss by caloric restriction is associated with an increase in circulating ghrelin concentrations.

    “Weight loss by caloric restriction is associated with an increase in circulating concentrations of ghrelin (9).”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [9] Cummings DE, Weigle DS, Frayo RS, Breen PA, Ma MK, Dellinger EP et al. Plasma ghrelin levels after diet-induced weight loss or gastric bypass surgery. N Engl J Med 2002; 346: 1623–1630. source

      Not checked in the free run.

  • Classified as probably not a substantial claim. May combine two claims.

    Premisecitation

    PYY and GLP-1 decrease appetite, increase satiety, slow gut motility, and improve insulin sensitivity.

    “Both peptides decrease appetite, increase satiety, slow gut motility and improve insulin sensitivity (7).”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites [7] Vincent RP, Ashrafian H, le Roux CW . Mechanisms of disease: the role of gastrointestinal hormones in appetite and obesity. Nat Clin Pract 2008; 5: 268–277. source

      Not checked in the free run.

  • Classified as probably not a substantial claim.

    Study design and conductnone given

    Body composition analysis was not performed.

    “A limitation of this study is that body composition analysis was not performed.”
    Quote in the paperSubstantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing), S4 (based).

    Study design and conductnone given

    Measurement of peripheral leptin levels may not accurately reflect leptin levels reaching TRH neurons in the central nervous system.

    “Furthermore, measurement of peripheral levels may not accurately reflect leptin levels reaching TRH neurons with the central nervous system.”
    Quote in the paperNot a substantial claim
34 of 34

  • The paper relies on this without support.

    The non-randomized LAGB and RYGB groups are comparable enough that between-group differences in outcomes can be attributed to the procedures.

    “The choice of bariatric procedure was based on the preference of surgeon and patient.”
    “body weight (112 ± 5 vs 128 ± 5 kg; P = 0.056) and BMI (41 ± 1 vs 48 ± 1 kg/m2; P < 0.001) were less in LAGB compared with RYGB.”

  • The paper relies on this without support.

    Most subjects had not reached their nadir weight at 1 year.

    “Since most of our subjects were unlikely to have achieved their nadir weight at 1 year, it may be too early to detect significant correlations between levels of L cell peptides and ultimate response to surgery.”
2 of 2

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Authors
Korner, J., Inabnet, W., Febres, G., Conwell, I. M., McMahon, D. J., Salas, R., Taveras, C., Schrope, B., & Bessler, M.
Affiliations
Columbia University (US)
ORCID
Venue
International Journal of Obesity
Publisher
Springer Science and Business Media LLC
Published
2009-05-05
Volume
33
Issue
7
Pages
786-795
ISSN
  • 0307-0565 (ISSN-L)
  • 1476-5497
DOI
10.1038/ijo.2009.79
PMC
PMC2710396
OpenAlex
W2082780134
Semantic Scholar
d9640aa77abc9b002cd79a200debf4a6726df0b6
Cited by
338
References
46
Citations by year
2026: 7 · 2025: 7 · 2024: 5 · 2023: 9 · 2022: 8 · 2021: 12 · 2020: 17 · 2019: 18 · 2018: 14 · 2017: 22 · 2016: 22 · 2015: 33 · 2014: 28 · 2013: 32 · 2012: 33
FWCI
35.15
Type
journal article
Language
en
Open access
Licence
www.springer.com/tdm (tdm)
Locations
  • International Journal of Obesity (publishedVersion)
  • PubMed (publishedVersion)
  • PubMed Central (acceptedVersion)
Funders
  • National Institutes of Health
  • National Institute of Diabetes and Digestive and Kidney Diseases (R01DK072011, DK072011)
  • National Center for Research Resources (UL1RR024156, RR 00645, M01RR000645)
Topics
  • Health Sciences › Medicine › Surgery › Bariatric Surgery and Outcomes
  • Life Sciences › Neuroscience › Endocrine and Autonomic Systems › Regulation of Appetite and Obesity
  • Health Sciences › Medicine › Surgery › Minimally Invasive Surgical Techniques
Keywords
gastric banding, Roux-en-Y gastric bypass, bariatric surgery, gastrointestinal hormones, peptide YY, ghrelin, glucagon-like peptide-1, leptin, insulin resistance, weight loss, glucose homeostasis, thyroid hormones, energy homeostasis, postprandial hormone secretion, HOMA-IR, free T3
MeSH terms
Blood Glucose, Female, Humans, Insulin Resistance, Male, Middle Aged, Obesity, Morbid, Prospective Studies, Gastric Bypass, Gastroplasty, Weight Loss, Postprandial Period, Glucagon-Like Peptide 1

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