Observational studyAmerican journal of kidney diseases : the official journal of the National Kidney Foundation2025

Stopping Versus Continuing Metformin in Patients With Advanced CKD: A Nationwide Scottish Target Trial Emulation Study.

Emilie J Lambourg, Edouard L Fu, Stuart McGurnaghan, Bryan R Conway, Neeraj Dhaun, Christopher H Grant, Ewan R Pearson, Patrick B Mark, John Petrie, Helen Colhoun and 2 more

Abstract readObservational StudyComparative Study
In one paragraph

Observational study in American journal of kidney diseases : the official journal of the National Kidney Foundation, 2025. The graph read 4 numbers from its abstract, feeding 1 cell of the map, but none could be read as for or against, so it casts no vote. Cited by 3 papers.

4numbers the graph read from it
0cells of the map it votes in
3citing papers in PubMed
field-weighted citation impact
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.

Read, but not usablea number the graph found but could not read as for or against

All-cause mortalitycomparator not stated · t2d, ckdfeeds one cell of the map
HR 1.040.81 to 1.33
Marginal structural models confirmed the higher risk of all-cause mortality and similar risk of MACE in patients who stopped versus continued metformin (all-cause mortality: HR, 1.34 [95% CI, 1.08-1.67]; MACE: HR, 1.04 [95% CI, 0.81-1.33]).
All-cause mortalitycomparator not stated · t2d, ckdfeeds one cell of the map
HR 1.341.08 to 1.67
Marginal structural models confirmed the higher risk of all-cause mortality and similar risk of MACE in patients who stopped versus continued metformin (all-cause mortality: HR, 1.34 [95% CI, 1.08-1.67]; MACE: HR, 1.04 [95% CI, 0.81-1.33]).
All-cause mortalitycomparator not stated · t2d, ckdfeeds one cell of the map
HR 1.050.88 to 1.26
Compared with continuing metformin, stopping metformin was associated with a lower 3-year survival (63.7% [95% CI, 60.9-66.6] vs 70.5% [95% CI, 68.0-73.0]; HR, 1.26 [95% CI, 1.10-1.44]), and the incidence of MACE was similar between both strategies (HR, 1.05 [95% CI, 0.88-1.26]).
All-cause mortalitycomparator not stated · t2d, ckdfeeds one cell of the map
HR 1.261.10 to 1.44
Compared with continuing metformin, stopping metformin was associated with a lower 3-year survival (63.7% [95% CI, 60.9-66.6] vs 70.5% [95% CI, 68.0-73.0]; HR, 1.26 [95% CI, 1.10-1.44]), and the incidence of MACE was similar between both strategies (HR, 1.05 [95% CI, 0.88-1.26]).

clause the extractor read what became the number

2 · Its place on the map

Where it lands on the map

Rows are treatments, columns are outcomes. The coloured squares are the cells this paper feeds, coloured by the vote it casts there. Click one to jump to what this paper adds to it.

supports the treatmentfavours the comparatorno clear differenceread, but no usable result
3 · What it changes

What it adds to each cell

For every cell the paper feeds: the belief in the claim with and without this paper, and this paper's estimate drawn against every other readable study in the cell. The ringed dot is this paper.

Metformin×all-cause mortality

No readable resultOpen on the map →What to test next →

1 readable study in this cell: 0 favour the treatment, 1 find no difference, 0 favour the comparator.

Belief with this paper
0.50one trial · 1 family supports, 0 contradict · against placebo
Without itNot a counted family in this claim, so removing it changes nothing.
← favours the treatmentfavours the comparator →
1 · no effect
NCT000387272,779 enrolled · 1996
HR 0.990.79 to 1.25

This paper's own estimate is on a different scale from the rest of the cell, so it is not drawn here.

4 · 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.

5 · Its place in the literature

Who cites it

3 citing papers in PubMed.

  1. Observational
  2. Article
  3. Metformin Alone and in Combinations Alter the Methylation Patterns ofEndocrine, metabolic & immune disorders drug targets · 2026
    Article
6 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

7 · Who and what money

Authors and funding

12 authors.

Emilie J LambourgDivision of Population Health and Genomics, School of Medicine, University of Dundee, Dundee.
Edouard L FuDivision of Pharmacoepidemiology and Pharmacoeconomics, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts; Department of Clinical Epidemiology, Leiden University Medical Center, Leiden, the Netherlands.
Stuart McGurnaghanDepartment of Clinical Epidemiology, Leiden University Medical Center, Leiden, the Netherlands.
Bryan R ConwayInstitute of Genetics and Molecular Medicine, University of Edinburgh, Edinburgh.
Neeraj DhaunInstitute of Genetics and Molecular Medicine, University of Edinburgh, Edinburgh.
Christopher H GrantDivision of Population Health and Genomics, School of Medicine, University of Dundee, Dundee.
Ewan R PearsonDivision of Population Health and Genomics, School of Medicine, University of Dundee, Dundee.
Patrick B MarkSchool of Cardiovascular & Metabolic Health, College of Medical, Veterinary & Life Sciences, University of Glasgow, Glasgow, United Kingdom.
John PetrieSchool of Health and Wellbeing, College of Medical, Veterinary & Life Sciences, University of Glasgow, Glasgow, United Kingdom.
Helen ColhounInstitute of Genetics and Molecular Medicine, University of Edinburgh, Edinburgh.
Samira BellDivision of Population Health and Genomics, School of Medicine, University of Dundee, Dundee. Electronic address: s.t.bell@dundee.ac.uk.
Scottish Diabetes Research Network Epidemiology Group

Funding

No grant is acknowledged in the PubMed record.

8 · The paper itself

Abstract

The marked sentences are the ones the graph read a number from.

RATIONALE &

objectiveDespite a lack of supporting evidence, current guidance recommends against the use of metformin in people with advanced kidney impairment. This observational study compared the outcomes of patients with type 2 diabetes who continued versus stopped metformin after developing stage 4 chronic kidney disease (CKD) (estimated glomerular filtration rate [eGFR]<30mL/min/1.73m STUDY

designNationwide observational cohort study. SETTING &

participantsAll adults with type 2 diabetes and incident stage 4 CKD in Scotland who were treated with metformin between January 2010 and April 2019. EXPOSURE: Stopping versus continuing metformin within 6 months following incident stage 4 CKD. OUTCOME: Primary outcome was all-cause mortality. Secondary outcomes included major adverse cardiovascular events (MACE). ANALYTICAL APPROACH: Target trial emulation with clone-censor-weight design and marginal structural models fit for sensitivity analyses.

resultsIn a population of 371,742 Scottish residents with a diagnosis of type 2 diabetes before April 30, 2019, 4,278 were identified as prevalent metformin users with incident CKD stage 4. Within 6 months of developing CKD stage IV, 1,713 (40.1%) individuals discontinued metformin. Compared with continuing metformin, stopping metformin was associated with a lower 3-year survival (63.7% [95% CI, 60.9-66.6] vs 70.5% [95% CI, 68.0-73.0]; HR, 1.26 [95% CI, 1.10-1.44]), and the incidence of MACE was similar between both strategies (HR, 1.05 [95% CI, 0.88-1.26]). Marginal structural models confirmed the higher risk of all-cause mortality and similar risk of MACE in patients who stopped versus continued metformin (all-cause mortality: HR, 1.34 [95% CI, 1.08-1.67]; MACE: HR, 1.04 [95% CI, 0.81-1.33]). LIMITATIONS: Residual confounding.

conclusionsThe continued use of metformin may be appropriate when eGFR falls below 30mL/min/1.73m PLAIN-LANGUAGE SUMMARY: Current guidance recommends against the use of metformin in people with advanced kidney impairment despite a lack of evidence. It is therefore currently unclear how the decision to stop versus continue metformin in patients who reach stage 4 CKD impacts their risk of mortality and cardiovascular events. This study showed that stopping metformin after reaching stage 4 CKD was associated with reduced survival that did not appear to be mediated by an increase in adverse cardiovascular outcomes. These findings may support the continued use of metformin in patients with advanced kidney impairment, but further research is needed to confirm these observations.

Indexed as

Diabetes Mellitus, Type 2Hypoglycemic AgentsMetforminRenal Insufficiency, ChronicWithholding TreatmentAgedCohort StudiesFemaleGlomerular Filtration RateHumansMaleMiddle AgedScotlandHypoglycemic AgentsMetforminChronic kidney diseasediabetesepidemiologymetformintarget trial emulation

Identifiers

PMID39521399
PMCPMC12101959

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.