Evidence map›Paper›PMID 41854997›Full record

SynthesisObesity surgery2026

Hormone PYY does not Explain the Variability in Weight Loss After Roux-en-Y Gastric Bypass: Evidence From a Meta-Analysis.

Giovanna Macanhã Scremin, Pedro Bicudo Bregion, Ana Cláudia Portes Nascimento, Júlia Marchiori Fein, Leonardo Halamy Pereira, Victor Kenzo Ivano, Everton Cazzo

Abstract readMeta-AnalysisSystematic Review
In one paragraph

Synthesis in Obesity surgery, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Not yet cited in PubMed.

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0citing papers in PubMed
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1 · What the graph read from it

What it found

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The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

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3 · Its place in the literature

Who cites it

0 citing papers in PubMed.

No citing paper in PubMed yet.

4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

7 authors.

Giovanna Macanhã ScreminPontifícia Universidade Católica do Paraná, Curitiba, Brazil.
Pedro Bicudo BregionState University of Campinas, Campinas, Brazil.
Ana Cláudia Portes NascimentoClinics Hospital of Ribeirão Preto, Ribeirão Preto, Brazil.
Júlia Marchiori FeinState University of Campinas, Campinas, Brazil.
Leonardo Halamy PereiraFluminense Federal University, Niterói, Brazil.
Victor Kenzo IvanoState University of Campinas, Campinas, Brazil.
Everton CazzoState University of Campinas, Campinas, Brazil. notrevezzo@yahoo.com.br.

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

backgroundPeptide YY (PYY) plays a key role in postprandial satiety and is markedly increased after Roux-en-Y gastric bypass (RYGB). While GLP-1 has been widely studied, the role of PYY as a predictor of weight loss success remains unclear. Some patients are considered non-responders, achieving < 50% excess BMI loss (EBMIL) or experiencing significant weight regain. This systematic review and meta-analysis aimed to compare fasting PYY levels and postprandial area under the curve (AUC) between RYGB responders and non-responders.

methodsFollowing PRISMA guidelines, PubMed, Embase, and Cochrane databases were searched for observational or interventional studies assessing PYY in adult RYGB patients stratified by weight loss response. Primary outcomes were fasting PYY levels and PYY AUC after standardized meals. Random-effects meta-analysis was conducted using Review Manager 5.4. Mean differences (MD) with 95% confidence intervals (CI) were calculated. Heterogeneity was assessed via Cochran’s Q and I².

resultsFive studies were included in the systematic review (92 non-responders and 89 responders), contributing to the fasting PYY meta-analysis, which showed no significant difference between groups (MD 1.71 pg/mL; 95% CI − 5.22 to 8.63; I² = 0%). Four studies reported AUC, also showing no difference (MD 53.16 pg·min/mL; 95% CI − 1726.29 to 1832.61; I² = 0%). Several studies observed lower satiety scores and attenuated appetite suppression in non-responders despite similar PYY profiles. No significant genetic variants in PYY or its receptor were associated with weight loss outcomes.

conclusionRYGB responders and non-responders have comparable fasting and postprandial PYY concentrations. These findings suggest that differential weight loss after RYGB is likely mediated by factors beyond PYY secretion, including neural, behavioral, or other hormonal mechanisms.

Indexed as

Gastric BypassObesity, MorbidPeptide YYWeight LossFastingHumansPostprandial PeriodPeptide YYBariatric surgeryGastric bypassIncretinsPeptide YYTreatment failureWeight loss

Identifiers

PMID41854997
PMCPMC13083511

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Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.