Evidence map›Paper›PMID 26185175›Full record

SynthesisBMJ open2015

Anaemia and related nutrient deficiencies after Roux-en-Y gastric bypass surgery: a systematic review and meta-analysis.

Ting-Chia Weng, Chia-Hsuin Chang, Yaa-Hui Dong, Yi-Cheng Chang, Lee-Ming Chuang

Open access · goldAbstract readMeta-AnalysisSystematic Review
PubMed Full text at PMC Publisher
In one paragraph

Synthesis in BMJ open, 2015. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 71 papers, 9 of them syntheses that pooled it.

0numbers the graph read from it
0cells of the map it votes in
71citing papers in PubMed, 9 pooled it
10.9field-weighted citation impact, top 1% of its field
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

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

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

71 citing papers in PubMed, 9 syntheses or guidelines pooled it, 164 citations in OpenAlex.

  1. Pooled it
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  3. One Anastomosis Gastric Bypass Versus Sleeve Gastrectomy for Obesity: a Systemic Review and Meta-analysis.Journal of gastrointestinal surgery : official journal of the Society for Surgery of the Alimentary Tract · 2023
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  9. Oral Vitamin BObesity surgery · 2018
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11 more citing papers are in PubMed but not listed here.

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

5 authors at 3 institutions in 2 countries.

Ting-Chia WengDepartment of Medicine, College of Medicine, National Taiwan University, Taipei, Taiwan.
Chia-Hsuin ChangDepartment of Medicine, College of Medicine, National Taiwan University, Taipei, Taiwan Department of Internal Medicine, National Taiwan University Hospital, Taipei, Taiwan Institute of Preventive Medicine, College of Public Health, National Taiwan University, Taipei, Taiwan.
Yaa-Hui DongDivision of Pharmacoepidemiology and Pharmacoeconomics, Department of Medicine, Brigham and Women's Hospital, Boston, Massachusetts, USA.
Yi-Cheng ChangDepartment of Internal Medicine, National Taiwan University Hospital, Taipei, Taiwan Graduate Institute of Medical Genomics and Proteomics, National Taiwan University, Taipei, Taiwan.
Lee-Ming ChuangDepartment of Medicine, College of Medicine, National Taiwan University, Taipei, Taiwan Department of Internal Medicine, National Taiwan University Hospital, Taipei, Taiwan Institute of Preventive Medicine, College of Public Health, National Taiwan University, Taipei, Taiwan.
National Taiwan University · TWNational Taiwan University Hospital · TWBrigham and Women's Hospital · US

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

objectiveTo obtain a pooled risk estimate on the long-term impact of anaemia and related nutritional deficiencies in patients receiving Roux-en-Y gastric bypass (RYGB) surgery.

designSystematic review and meta-analysis. DATA SOURCES: MEDLINE, EMBASE and Cochrane databases were searched to identify English reports published before 16 May 2014. ELIGIBILITY CRITERIA: Articles with case numbers >100, follow-up period >12 months, and complete data from both before and after surgery were selected. Outcomes of interest were changes in baseline measurements of proportion of patients with anaemia, by haemoglobin, haematocrit, ferritin, iron, vitamin B12 and folate levels. DATA COLLECTION AND ANALYSIS: Two reviewers independently reviewed data and selected six prospective and nine retrospective studies with a total of 5909 patients. A random effect model with inverse variance weighting was used to calculate summary estimates of outcomes at 6, 12, 24 and 36 months postoperatively.

resultsProportion of patients with anaemia was 12.2% at baseline, which, respectively, increased to 20.9% and 25.9% at 12 and 24 months follow-up, consistent with decreases in haemoglobin and haematocrit levels. Although the serum iron level did not change substantially after surgery, the frequency of patients with ferritin deficiency increased from 7.9% at baseline to 13.4% and 23.0% at 12 and 24 months, respectively, postoperation. Vitamin B12 deficiency increased from 2.3% at baseline to 6.5% at 12 months after surgery in those subjects receiving RYGB. There was no obvious increase in folate deficiency.

conclusionsRYGB surgery is associated with an increased risk of anaemia and deficiencies of iron and vitamin B12, but not folate. Ferritin is more sensitive when serum iron level is within normal range.

Indexed as

AnemiaFerritinsGastric BypassHumansIronObesity, MorbidPostoperative PeriodVitamin B 12 DeficiencyFerritinsIronAnemiaFerritinIronNutritional AnemiaRoux-en-Y Gastric Bypass

Identifiers

PMID26185175
PMCPMC4513480
OpenAlexW1923916119

What OpenQuestion holds

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Registered trials

None linked

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.