Evidence mapPaperPMID 40512873Full record

SynthesisEndocrinology, diabetes & metabolism2025

An Updated Systematic Review and Meta-Analysis on the Efficacy and Safety of Metformin as Add-on Therapy to Insulin in Patients With Type 1 Diabetes.

Mohammad Mahdi Masouri, Rasoul Ebrahimi, Shokoofe Noori

Abstract readMeta-AnalysisSystematic Review
In one paragraph

Synthesis in Endocrinology, diabetes & metabolism, 2025. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 3 papers.

0numbers 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.

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

3 citing papers in PubMed.

  1. Article
  2. Article
  3. 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

3 authors.

Mohammad Mahdi MasouriSchool of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran.ORCID https://orcid.org/0009-0009-4243-5698
Rasoul EbrahimiSchool of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
Shokoofe NooriDepartment of Biochemistry, Faculty of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran.

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

introductionThis study aims to perform an updated meta-analysis evaluating the efficacy and safety of metformin adjunct therapy in type 1 diabetes mellitus (T1DM) patients.

methodCochrane, PubMed and Embase were searched for randomised controlled trials (RCTs) that reported the efficacy and safety of metformin in T1DM patients. Statistical analyses were performed using STATA software.

resultsTwenty-nine placebo-controlled RCTs enrolling 2051 T1DM patients were included. Adolescents experienced a notable reduction in total insulin daily dose (TIDD) (mean difference [MD] = -0.61 [95% confidence interval (CI): -1.02, -0.20] units/kg per day) and levels of haemoglobin A1c (HbA1c) (MD = -0.45 [95% CI: -0.79, -0.11]), total cholesterol (TC) (MD = -0.78 [95% CI: -1.54, -0.02]), and low-density lipoprotein (LDL) (MD = -0.69 [95% CI: -1.36, -0.02]) at 3 months of follow-up with metformin. In adults, metformin significantly reduced Body Mass Index (BMI) (MD = -0.71 [95% CI: -1.23, -0.19]), TIDD (MD = -0.44 [95% CI: -0.73, -0.16]), and levels of HbA1c (MD = -0.70 [95% CI: -1.10, -0.30]) and TC (MD = -0.60 [95% CI: -1.09, -0.10]) at 6 months. The risk of gastrointestinal adverse events (GIAEs) was significantly higher in both adolescents (Relative Risk [RR] = 1.74 [95% CI: 1.38, 2.21]) and adults (RR = 3.24 [95% CI: 1.49, 7.02]). All of the above had p-values less than 0.05. The metformin group showed no differences in BMI Z-score, high-density lipoprotein (HDL) level, or diabetic ketoacidosis (DKA) risk. No statistical difference was identified for any of the outcomes at other follow-up endpoints.

conclusionsMetformin may reduce TIDD and levels of HbA1c, TC, triglycerides (TG), and LDL in T1DM adolescents. BMI, TIDD, and levels of HbA1c and TC may decrease in adults. Moreover, it may raise the risk of GIAEs in both age groups.

Indexed as

Diabetes Mellitus, Type 1Hypoglycemic AgentsInsulinMetforminAdolescentDrug Therapy, CombinationGlycated HemoglobinHumansRandomized Controlled Trials as TopicTreatment OutcomeGlycated HemoglobinHypoglycemic AgentsInsulinMetforminmeta‐analysismetformintype 1 diabetes mellitus

Identifiers

PMID40512873
PMCPMC12165280

What Socratic holds

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Registered trials

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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.