Evidence map›Paper›PMID 38272537›Full record

Observational studyBMJ open diabetes research & care2024

Incident dementia risk among patients with type 2 diabetes receiving metformin versus alternative oral glucose-lowering therapy: an observational cohort study using UK primary healthcare records.

William Doran, Louis Tunnicliffe, Rutendo Muzambi, Christopher T Rentsch, Krishnan Bhaskaran, Liam Smeeth, Carol Brayne, Dylan M Williams, Nish Chaturvedi, Sophie V Eastwood and 3 more

Open access · goldAbstract readObservational Study
PubMed Full text at PMC Publisher
In one paragraph

Observational study in BMJ open diabetes research & care, 2024. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 5 papers, 1 of them a synthesis that pooled it.

0numbers the graph read from it
0cells of the map it votes in
5citing papers in PubMed, 1 pooled it
2.3field-weighted citation impact, top 12% 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

5 citing papers in PubMed, 1 synthesis or guideline pooled it, 7 citations in OpenAlex.

  1. Pooled it
  2. Journal of Alzheimer's disease : JAD · 2026
    Article
  3. Article
  4. Review
  5. Review
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

13 authors at 6 institutions in 2 countries.

William DoranFaculty of Epidemiology and Population Health, London School of Hygiene & Tropical Medicine, London, UK.
Louis TunnicliffeFaculty of Epidemiology and Population Health, London School of Hygiene & Tropical Medicine, London, UK.
Rutendo MuzambiFaculty of Epidemiology and Population Health, London School of Hygiene & Tropical Medicine, London, UK.
Christopher T RentschFaculty of Epidemiology and Population Health, London School of Hygiene & Tropical Medicine, London, UK.ORCID 0000-0002-1408-7907
Krishnan BhaskaranFaculty of Epidemiology and Population Health, London School of Hygiene & Tropical Medicine, London, UK.
Liam SmeethFaculty of Epidemiology and Population Health, London School of Hygiene & Tropical Medicine, London, UK.
Carol BrayneCambridge Public Health, University of Cambridge, Cambridge, UK.
Dylan M WilliamsMRC Unit for Lifelong Health and Ageing, University College London, London, UK.
Nish ChaturvediMRC Unit for Lifelong Health and Ageing, University College London, London, UK.
Sophie V EastwoodMRC Unit for Lifelong Health and Ageing, University College London, London, UK.
Susanna J DunachieNDM Centre for Global Health Research, Nuffield Department of Medicine, University of Oxford, Oxford, UK.
Rohini MathurCentre for Primary Care, Wolfson Institute of Population Health, Queen Mary University of London, London, UK.
Charlotte Warren-GashFaculty of Epidemiology and Population Health, London School of Hygiene & Tropical Medicine, London, UK charlotte.warren-gash1@lshtm.ac.uk.ORCID 0000-0003-4524-3180
London School of Hygiene & Tropical Medicine · GBMRC Unit for Lifelong Health and Ageing · GBQueen Mary University of London · GBUniversity of Cambridge · GBUniversity of Oxford · GBYale University · US

Funding

Wellcome Trust 201440/Z/16/ZWellcome Trust 220283/Z/20/ZWellcome Trust 225868Wellcome Trust 225868/Z/22/Z
6 · The paper itself

Abstract

introduction4.2 million individuals in the UK have type 2 diabetes, a known risk factor for dementia and mild cognitive impairment (MCI). Diabetes treatment may modify this association, but existing evidence is conflicting. We therefore aimed to assess the association between metformin therapy and risk of incident all-cause dementia or MCI compared with other oral glucose-lowering therapies (GLTs). RESEARCH DESIGN AND

methodsWe conducted an observational cohort study using the Clinical Practice Research Datalink among UK adults diagnosed with diabetes at ≥40 years between 1990 and 2019. We used an active comparator new user design to compare risks of dementia and MCI among individuals initially prescribed metformin versus an alternative oral GLT using Cox proportional hazards regression controlling for sociodemographic, lifestyle and clinical confounders. We assessed for interaction by age and sex. Sensitivity analyses included an as-treated analysis to mitigate potential exposure misclassification.

resultsWe included 211 396 individuals (median age 63 years; 42.8% female), of whom 179 333 (84.8%) initiated on metformin therapy. Over median follow-up of 5.4 years, metformin use was associated with a lower risk of dementia (adjusted HR (aHR) 0.86 (95% CI 0.79 to 0.94)) and MCI (aHR 0.92 (95% CI 0.86 to 0.99)). Metformin users aged under 80 years had a lower dementia risk (aHR 0.77 (95% CI 0.68 to 0.85)), which was not observed for those aged ≥80 years (aHR 0.95 (95% CI 0.87 to 1.05)). There was no interaction with sex. The as-treated analysis showed a reduced effect size compared with the main analysis (aHR 0.90 (95% CI 0.83 to 0.98)).

conclusionsMetformin use was associated with lower risks of incident dementia and MCI compared with alternative GLT among UK adults with diabetes. While our findings are consistent with a neuroprotective effect of metformin against dementia, further research is needed to reduce risks of confounding by indication and assess causality.

Indexed as

DementiaDiabetes Mellitus, Type 2MetforminAdultCohort StudiesFemaleGlucoseHumansHypoglycemic AgentsMaleMiddle AgedPrimary Health CareUnited KingdomGlucoseHypoglycemic AgentsMetforminDementiaDiabetes Mellitus, Type 2Electronic Health RecordsMetformin

Identifiers

PMID38272537
PMCPMC10823924
OpenAlexW4391234872

What Socratic holds

Texttitle and abstract
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.