Evidence mapPaperPMID 27898682Full record

SynthesisPLoS medicine2016

Genetic Predisposition to an Impaired Metabolism of the Branched-Chain Amino Acids and Risk of Type 2 Diabetes: A Mendelian Randomisation Analysis.

Luca A Lotta, Robert A Scott, Stephen J Sharp, Stephen Burgess, Jian'an Luan, Therese Tillin, Amand F Schmidt, Fumiaki Imamura, Isobel D Stewart, John R B Perry and 18 more

Open access · goldAbstract readMeta-Analysis
In one paragraph

Synthesis in PLoS medicine, 2016. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 262 papers, 8 of them syntheses that pooled it.

0numbers the graph read from it
0cells of the map it votes in
262citing papers in PubMed, 8 pooled it
18.5field-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

262 citing papers in PubMed, 8 syntheses or guidelines pooled it, 420 citations in OpenAlex.

  1. Pooled it
  2. Use of Mendelian Randomization to Unveil Metabolic Markers inJournal of Korean medical science · 2026
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202 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

28 authors at 6 institutions in 3 countries.

Luca A LottaMRC Epidemiology Unit, University of Cambridge, Cambridge, United Kingdom.
Robert A ScottMRC Epidemiology Unit, University of Cambridge, Cambridge, United Kingdom.
Stephen J SharpMRC Epidemiology Unit, University of Cambridge, Cambridge, United Kingdom.ORCID http://orcid.org/0000-0003-2375-1440
Stephen BurgessDepartment of Public Health and Primary Care, University of Cambridge, Cambridge, United Kingdom.ORCID http://orcid.org/0000-0001-5365-8760
Jian'an LuanMRC Epidemiology Unit, University of Cambridge, Cambridge, United Kingdom.
Therese TillinInstitute of Cardiovascular Science, Faculty of Population Health, University College London, London, United Kingdom.
Amand F SchmidtInstitute of Cardiovascular Science, Faculty of Population Health, University College London, London, United Kingdom.ORCID http://orcid.org/0000-0003-1327-0424
Fumiaki ImamuraMRC Epidemiology Unit, University of Cambridge, Cambridge, United Kingdom.ORCID http://orcid.org/0000-0002-6841-8396
Isobel D StewartMRC Epidemiology Unit, University of Cambridge, Cambridge, United Kingdom.
John R B PerryMRC Epidemiology Unit, University of Cambridge, Cambridge, United Kingdom.
Luke MarneyMRC Human Nutrition Research, Cambridge, United Kingdom.ORCID http://orcid.org/0000-0001-8117-8246
Albert KoulmanMRC Human Nutrition Research, Cambridge, United Kingdom.ORCID http://orcid.org/0000-0001-9998-051X
Edward D KarolyMetabolon, Morrisville, North Carolina, United States of America.
Nita G ForouhiMRC Epidemiology Unit, University of Cambridge, Cambridge, United Kingdom.
Rasmus J O SjögrenDepartment of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm, Sweden.ORCID http://orcid.org/0000-0002-0640-8504
Erik NäslundDivision of Surgery, Department of Clinical Sciences, Danderyd Hospital, Karolinska Institutet, Stockholm, Sweden.ORCID http://orcid.org/0000-0002-0166-6344
Juleen R ZierathDepartment of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm, Sweden.
Anna KrookDepartment of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden.ORCID http://orcid.org/0000-0002-0891-0258
David B SavageMetabolic Research Laboratories, Institute of Metabolic Science, University of Cambridge, Cambridge, United Kingdom.
Julian L GriffinMRC Human Nutrition Research, Cambridge, United Kingdom.
Nishi ChaturvediInstitute of Cardiovascular Science, Faculty of Population Health, University College London, London, United Kingdom.ORCID http://orcid.org/0000-0002-6211-2775
Aroon D HingoraniInstitute of Cardiovascular Science, Faculty of Population Health, University College London, London, United Kingdom.
Kay-Tee KhawDepartment of Public Health and Primary Care, University of Cambridge, Cambridge, United Kingdom.
Inês BarrosoMetabolic Research Laboratories, Institute of Metabolic Science, University of Cambridge, Cambridge, United Kingdom.ORCID http://orcid.org/0000-0001-5800-4520
Mark I McCarthyOxford Centre for Diabetes, Endocrinology and Metabolism, and Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford, United Kingdom.ORCID http://orcid.org/0000-0002-4393-0510
Stephen O'RahillyMetabolic Research Laboratories, Institute of Metabolic Science, University of Cambridge, Cambridge, United Kingdom.
Nicholas J WarehamMRC Epidemiology Unit, University of Cambridge, Cambridge, United Kingdom.ORCID http://orcid.org/0000-0003-1422-2993
Claudia LangenbergMRC Epidemiology Unit, University of Cambridge, Cambridge, United Kingdom.
University of Cambridge · GBKarolinska Institutet · SEUniversity College London · GBMRC Human Nutrition Research · GBCentre for Human Genetics · GBMetabolon (United States) · US

Funding

British Heart Foundation RG/10/12/28456Cancer Research UK 14136Medical Research Council G0401527Medical Research Council G0800270Medical Research Council G1000143Medical Research Council MC_EX_MR/L100002/1Medical Research Council MC_PC_13030Medical Research Council MC_UP_A090_1006Medical Research Council MC_UU_00002/7Medical Research Council MC_UU_12012/5Medical Research Council MC_UU_12015/1Medical Research Council MR/K006584/1Medical Research Council MR/N003284/1Medical Research Council MR/P011705/1Medical Research Council MR/P01836X/1Wellcome Trust 090532Wellcome Trust 098381Wellcome Trust 107064
6 · The paper itself

Abstract

backgroundHigher circulating levels of the branched-chain amino acids (BCAAs; i.e., isoleucine, leucine, and valine) are strongly associated with higher type 2 diabetes risk, but it is not known whether this association is causal. We undertook large-scale human genetic analyses to address this question. METHODS AND

findingsGenome-wide studies of BCAA levels in 16,596 individuals revealed five genomic regions associated at genome-wide levels of significance (p < 5 × 10-8). The strongest signal was 21 kb upstream of the PPM1K gene (beta in standard deviations [SDs] of leucine per allele = 0.08, p = 3.9 × 10-25), encoding an activator of the mitochondrial branched-chain alpha-ketoacid dehydrogenase (BCKD) responsible for the rate-limiting step in BCAA catabolism. In another analysis, in up to 47,877 cases of type 2 diabetes and 267,694 controls, a genetically predicted difference of 1 SD in amino acid level was associated with an odds ratio for type 2 diabetes of 1.44 (95% CI 1.26-1.65, p = 9.5 × 10-8) for isoleucine, 1.85 (95% CI 1.41-2.42, p = 7.3 × 10-6) for leucine, and 1.54 (95% CI 1.28-1.84, p = 4.2 × 10-6) for valine. Estimates were highly consistent with those from prospective observational studies of the association between BCAA levels and incident type 2 diabetes in a meta-analysis of 1,992 cases and 4,319 non-cases. Metabolome-wide association analyses of BCAA-raising alleles revealed high specificity to the BCAA pathway and an accumulation of metabolites upstream of branched-chain alpha-ketoacid oxidation, consistent with reduced BCKD activity. Limitations of this study are that, while the association of genetic variants appeared highly specific, the possibility of pleiotropic associations cannot be entirely excluded. Similar to other complex phenotypes, genetic scores used in the study captured a limited proportion of the heritability in BCAA levels. Therefore, it is possible that only some of the mechanisms that increase BCAA levels or affect BCAA metabolism are implicated in type 2 diabetes.

conclusionsEvidence from this large-scale human genetic and metabolomic study is consistent with a causal role of BCAA metabolism in the aetiology of type 2 diabetes.

Indexed as

Genetic Predisposition to DiseaseMendelian Randomization AnalysisAdultAgedAmino Acids, Branched-ChainDiabetes Mellitus, Type 2Genome-Wide Association StudyHumansMaleMiddle AgedProspective StudiesRisk FactorsSwedenYoung AdultAmino Acids, Branched-Chain

Identifiers

PMID27898682
PMCPMC5127513
OpenAlexW2559236589

What Socratic holds

Textmetadata
LicenceCC BY
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 Socratic graph.