Evidence map›Paper›PMID 30382463›Full record

SynthesisObesity surgery2019

Impact of Bariatric Surgery on Male Sex Hormones and Sperm Quality: a Systematic Review and Meta-Analysis.

Yung Lee, Jerry T Dang, Noah Switzer, James Yu, Chunhong Tian, Daniel W Birch, Shahzeer Karmali

Abstract readMeta-AnalysisSystematic Review
PubMed Publisher
In one paragraph

Synthesis in Obesity surgery, 2019. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 48 papers, 6 of them syntheses that pooled it.

0numbers the graph read from it
0cells of the map it votes in
48citing papers in PubMed, 6 pooled it
6.0field-weighted citation impact, top 3% 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

48 citing papers in PubMed, 6 syntheses or guidelines pooled it, 83 citations in OpenAlex.

  1. Effect of Roux-en-Y Gastric Bypass and Sleeve Gastrectomy on Male Sexual Function: A Systematic Review and Meta-Analysis.Obesity reviews : an official journal of the International Association for the Study of Obesity · 2026
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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 at 2 institutions in 1 country.

Yung LeeMichael G. DeGroote School of Medicine, McMaster University, Hamilton, ON, Canada.
Jerry T DangDepartment of Surgery, University of Alberta, 8440 112 Street NW, Edmonton, AB, T6G 2B7, Canada. dang2@ualberta.ca.ORCID 0000-0001-8659-0934
Noah SwitzerDepartment of Surgery, University of Alberta, 8440 112 Street NW, Edmonton, AB, T6G 2B7, Canada.
James YuMichael G. DeGroote School of Medicine, McMaster University, Hamilton, ON, Canada.
Chunhong TianDepartment of Surgery, University of Alberta, 8440 112 Street NW, Edmonton, AB, T6G 2B7, Canada.
Daniel W BirchDepartment of Surgery, University of Alberta, 8440 112 Street NW, Edmonton, AB, T6G 2B7, Canada.
Shahzeer KarmaliDepartment of Surgery, University of Alberta, 8440 112 Street NW, Edmonton, AB, T6G 2B7, Canada.
University of Alberta · CAMcMaster University · CA

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

This systematic review and meta-analysis aims to establish the effects of bariatric surgery on male sex hormones, sperm parameters, and sexual function. We searched MEDLINE, EMBASE, Web of Science, and Scopus from database inception through June 2018. Articles were eligible for inclusion if they examined the effect of bariatric surgery on male sex hormones and sperm parameters in patients with obesity. Primary outcomes of interest were sex hormones and sperm quality. Secondary outcome was sexual function (International Index of Erectile Function (IIEF) score). Pooled estimates were calculated using random effects meta-analysis. A total of 28 cohort studies with 1022 patients were identified from 3896 potentially relevant citations. Both free and calculated testosterone levels were significantly increased after bariatric surgery (mean difference (MD) - 7.47 nM, 95% CI - 8.62 to - 6.31, p < 0.001 and MD - 0.05 nM, 95% CI - 0.07 to - 0.02, p < 0.001, respectively). Consistent with the increase in testosterone, LH, FSH, and SHBG levels were also significantly increased after surgery. In contrast, free and total estradiol and prolactin levels were significantly decreased after bariatric surgery. From studies that reported the IIEF score, bariatric surgery led to a significant increase in erectile function after surgery (MD - 0.46, 95% CI - 0.89 to - 0.02, p = 0.04). However, bariatric surgery did not affect sperm quality, DHEA, androstenedione, and inhibin B levels. Sustained weight-loss induced by bariatric surgery had a significant effect on increasing male sex hormones and decreasing female sex hormones in male patients with obesity. However, sperm quality and function were not improved after surgery.

Indexed as

Bariatric SurgerySemen AnalysisCohort StudiesFemaleGonadal Steroid HormonesHumansMaleObesityObesity, MorbidTestosteroneWeight LossGonadal Steroid HormonesTestosteroneBariatric surgeryErectile functionEstrogenSex hormonesSperm qualityTestosterone

Identifiers

PMID30382463
OpenAlexW2898887253

What OpenQuestion holds

Textmetadata
Read underepoch 390

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.