Evidence map›Paper›PMID 25454317›Full record

ArticleParkinsonism & related disorders2014

Diabetes mellitus is independently associated with more severe cognitive impairment in Parkinson disease.

Nicolaas I Bohnen, Vikas Kotagal, Martijn L T M Müller, Robert A Koeppe, Peter J H Scott, Roger L Albin, Kirk A Frey, Myria Petrou

Open access · greenAbstract read
PubMed Full text at PMC Publisher
In one paragraph

Article in Parkinsonism & related disorders, 2014. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 57 papers, 3 of them syntheses that pooled it.

0numbers the graph read from it
0cells of the map it votes in
57citing papers in PubMed, 3 pooled it
4.3field-weighted citation impact, top 6% 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

57 citing papers in PubMed, 3 syntheses or guidelines pooled it, 110 citations in OpenAlex.

  1. Pooled it
  2. Pooled it
  3. Pooled it
  4. Article
  5. Review
  6. Review
  7. 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
  8. Lifestyle medicine in Parkinson's disease.Journal of neural transmission (Vienna, Austria : 1996) · 2026
    Review
  9. Parkinson Disease and the Gut: A Primer for Gastroenterologists.The American journal of gastroenterology · 2025
    Review
  10. Metformin as a potential neuroprotective agent that influence Parkinson's disease.Neurological sciences : official journal of the Italian Neurological Society and of the Italian Society of Clinical Neurophysiology · 2025
    Review
  11. Article
  12. Article
  13. Article
  14. Review
  15. Parkinson's disease and glucose metabolism impairment.Translational neurodegeneration · 2025
    Review
  16. Increased dementia risk in patients with Parkinson's disease attributed to metabolic syndrome.Neurological sciences : official journal of the Italian Neurological Society and of the Italian Society of Clinical Neurophysiology · 2025
    Article
  17. Review
  18. Article
  19. Article
  20. Update: Protective and risk factors for Parkinson disease.Parkinsonism & related disorders · 2024
    Review
4 · The record

Corrections and comments

5 · Who and what money

Authors and funding

8 authors at 1 institution in 1 country.

Nicolaas I BohnenDepartment of Radiology, University of Michigan, Ann Arbor, MI, USA; Department of Neurology, University of Michigan, Ann Arbor, MI, USA; Neurology Service and GRECC, VAAAHS, Ann Arbor, MI, USA. Electronic address: nbohnen@umich.edu.
Vikas KotagalDepartment of Neurology, University of Michigan, Ann Arbor, MI, USA.
Martijn L T M MüllerDepartment of Radiology, University of Michigan, Ann Arbor, MI, USA.
Robert A KoeppeDepartment of Radiology, University of Michigan, Ann Arbor, MI, USA.
Peter J H ScottDepartment of Radiology, University of Michigan, Ann Arbor, MI, USA.
Roger L AlbinDepartment of Neurology, University of Michigan, Ann Arbor, MI, USA; Neurology Service and GRECC, VAAAHS, Ann Arbor, MI, USA; Michigan Alzheimer Disease Center, Ann Arbor, MI, USA.
Kirk A FreyDepartment of Radiology, University of Michigan, Ann Arbor, MI, USA; Department of Neurology, University of Michigan, Ann Arbor, MI, USA.
Myria PetrouDepartment of Radiology, University of Michigan, Ann Arbor, MI, USA.
University of Michigan–Ann Arbor · US

Funding

Tomography and Data AnalysisP01NS015655 · NINDS · UNIVERSITY OF MICHIGAN AT ANN ARBOR · PI GILMAN, SID · 1985 to 2012
$13.0M
Hyposmia, Cholinergic Denervation and Incipient Cognitive Decline in PDR01NS070856 · NINDS · UNIVERSITY OF MICHIGAN AT ANN ARBOR · PI BOHNEN, NICOLAAS IDA · 2010 to 2014
$1.9M
IMAGING BIOMARKERS OF PROGRESSION OF MOBILITY IMPAIRMENT IN PDI01RX000317 · VA · VETERANS HEALTH ADMINISTRATION · PI BOHNEN, NICOLAAS IDA · 2012 to 2014
–
NINDS NIH HHS P01 NS015655NINDS NIH HHS R01 NS070856RRD VA I01 RX000317
6 · The paper itself

Abstract

backgroundThere is increasing interest in interactions between metabolic syndromes and neurodegeneration. Diabetes mellitus (DM) contributes to cognitive impairment in the elderly but its effect in Parkinson disease (PD) is not well studied.

objectiveTo investigate effects of comorbid DM on cognition in PD independent from PD-specific primary neurodegenerations.

methodsCross-sectional study. Patients with PD (n = 148); age 65.6 ± 7.4 years, Hoehn and Yahr stage 2.4 ± 0.6, with (n = 15) and without (n = 133) comorbid type II DM, underwent [(11)C]methyl-4-piperidinyl propionate (PMP) acetylcholinesterase (AChE) PET imaging to assess cortical cholinergic denervation, [(11)C]dihydrotetrabenazine (DTBZ) PET imaging to assess nigrostriatal denervation, and neuropsychological assessments. A global cognitive Z-score was calculated based on normative data. Analysis of covariance was performed to determine cognitive differences between subjects with and without DM while controlling for nigrostriatal denervation, cortical cholinergic denervation, levodopa equivalent dose and education covariates.

resultsThere were no significant differences in age, gender, Hoehn and Yahr stage or duration of disease between diabetic and non-diabetic PD subjects. There was a non-significant trend toward lower years of education in the diabetic PD subjects compared with non-diabetic PD subjects. PD diabetics had significantly lower mean (±SD) global cognitive Z-scores (-0.98 ± 1.01) compared to the non-diabetics (-0.36 ± 0.91; F = 7.78, P = 0.006) when controlling for covariate effects of education, striatal dopaminergic denervation, and cortical cholinergic denervation (total model F = 8.39, P < 0.0001).

conclusionDiabetes mellitus is independently associated with more severe cognitive impairment in PD likely through mechanisms other than disease-specific neurodegenerations.

Indexed as

AgedButyratesCarbon IsotopesCognition DisordersCross-Sectional StudiesDiabetes ComplicationsDiabetes MellitusFemaleHumansMaleMiddle AgedNeuroimagingNeuropsychological TestsParkinson DiseasePiperidinesPositron-Emission TomographyButyratesCarbon Isotopesdihydrotetrabenazinemethyl-4-piperidinyl n-butyratePiperidinesTetrabenazineAcetylcholineCognitive impairmentDiabetes mellitusDopamineParkinson diseasePET

Identifiers

PMID25454317
PMCPMC4314515
OpenAlexW1969034413

What OpenQuestion holds

Textmetadata
LicenceTDM
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.