Evidence map›Paper›PMID 33682937›Full record

SynthesisMovement disorders : official journal of the Movement Disorder Society2021

Type 2 Diabetes as a Determinant of Parkinson's Disease Risk and Progression.

Harneek Chohan, Konstantin Senkevich, Radhika K Patel, Jonathan P Bestwick, Benjamin M Jacobs, Sara Bandres Ciga, Ziv Gan-Or, Alastair J Noyce

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

Synthesis in Movement disorders : official journal of the Movement Disorder Society, 2021. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 126 papers, 3 of them syntheses that pooled it.

0numbers the graph read from it
0cells of the map it votes in
126citing papers in PubMed, 3 pooled it
18.0field-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

126 citing papers in PubMed, 3 syntheses or guidelines pooled it, 225 citations in OpenAlex.

  1. Pooled it
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  10. 8-Gingerol Mitigates MPPNeurochemical research · 2026
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  18. The impact of diabetes mellitus in prodromal Parkinson's disease.Neurological sciences : official journal of the Italian Neurological Society and of the Italian Society of Clinical Neurophysiology · 2026
    Article
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  20. Article

66 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

8 authors at 3 institutions in 3 countries.

Harneek ChohanPreventive Neurology Unit, Wolfson Institute of Preventive Medicine, Barts and the London School of Medicine and Dentistry, Queen Mary University of London, London, UK.ORCID 0000-0003-0561-758X
Konstantin SenkevichDepartment of Neurology and Neurosurgery, McGill University, Montréal, Quebec, Canada.
Radhika K PatelPreventive Neurology Unit, Wolfson Institute of Preventive Medicine, Barts and the London School of Medicine and Dentistry, Queen Mary University of London, London, UK.
Jonathan P BestwickPreventive Neurology Unit, Wolfson Institute of Preventive Medicine, Barts and the London School of Medicine and Dentistry, Queen Mary University of London, London, UK.
Benjamin M JacobsPreventive Neurology Unit, Wolfson Institute of Preventive Medicine, Barts and the London School of Medicine and Dentistry, Queen Mary University of London, London, UK.
Sara Bandres CigaMolecular Genetics Section, Laboratory of Neurogenetics, National Institute on Aging, National Institutes of Health, Bethesda, Maryland, USA.
Ziv Gan-OrDepartment of Neurology and Neurosurgery, McGill University, Montréal, Quebec, Canada.
Alastair J NoycePreventive Neurology Unit, Wolfson Institute of Preventive Medicine, Barts and the London School of Medicine and Dentistry, Queen Mary University of London, London, UK.ORCID 0000-0003-3027-5497
Queen Mary University of London · GBMontreal Neurological Institute and Hospital · CANational Institutes of Health · US

Funding

Canada First Research Excellence Fund (CFREF)Canadian Consortium on Neurodegeneration in Aging (CCNA)Fonds de recherche du Québec-Santé (FRQS)Intramural NIH HHS Z99 AG999999Intramural Research Program of the NIH, National Institute on AgingMichael J. Fox FoundationThe Barts CharityYoung Investigator Award by Parkinson Canada
6 · The paper itself

Abstract

backgroundType 2 diabetes (T2DM) and Parkinson's disease (PD) are prevalent diseases that affect an aging population. Previous systematic reviews and meta-analyses have explored the relationship between diabetes and the risk of PD, but the results have been conflicting.

objectiveThe objective was to investigate T2DM as a determinant of PD through a meta-analysis of observational and genetic summary data.

methodsA systematic review and meta-analysis of observational studies was undertaken by searching 6 databases. We selected the highest-quality studies investigating the association of T2DM with PD risk and progression. We then used Mendelian randomization (MR) to investigate the causal effects of genetic liability toward T2DM on PD risk and progression, using summary data derived from genome-wide association studies.

resultsIn the observational part of the study, pooled effect estimates showed that T2DM was associated with an increased risk of PD (odds ratio [OR] 1.21, 95% confidence interval [CI] 1.07-1.36), and there was some evidence that T2DM was associated with faster progression of motor symptoms (standardized mean difference [SMD] 0.55, 95% CI 0.39-0.72) and cognitive decline (SMD -0.92, 95% CI -1.50 to -0.34). Using MR, we found supportive evidence for a causal effect of diabetes on PD risk (inverse-variance weighted method [IVW] OR 1.08, 95% CI 1.02-1.14; P = 0.010) and some evidence of an effect on motor progression (IVW OR 1.10, 95% CI 1.01-1.20; P = 0.032) but not on cognitive progression.

conclusionsUsing meta-analyses of traditional observational studies and genetic data, we observed convincing evidence for an effect of T2DM on PD risk and new evidence to support a role in PD progression. © 2021 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.

Indexed as

Diabetes Mellitus, Type 2Parkinson DiseaseAgedCausalityGenome-Wide Association StudyHumansParkinson's diseasetype 2 diabetes

Identifiers

PMID33682937
PMCPMC9017318
OpenAlexW3135159820

What OpenQuestion 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 OpenQuestion graph.