Metformin treatment: evidence map - 19 findings across 19 sources

Evidence Landscape

This evidence map surveys 19 independent metformin treatment sources drawn from the Tier-2 corpus and classified as direct findings. They vary across population, comparator, and/or endpoint and are catalogued by source in the Findings Map rather than pooled into one estimate — cross-population aggregation is not claimed. Each row records its own population, comparator, endpoint, and effect, so the spread of the literature and any tensions between findings remain explicit.

Findings Map

Population	Comparator	Finding	Source
individuals with DM	—	metformin treatment has also been associated with reductions in chylomicrons by up to 50%	2025 doi:10.1007/s12325-025-03256-x
Caenorhabditis elegans	control	Metformin causes an 86% increase in S-adenosylmethionine (SAMe)	2025 doi:10.3390/ph18010055
participants in TAME trial	—	adequate power to detect a 20% reduction in the disease composite	2025 doi:10.21203/rs.3.rs-5920485/v1
patients	—	its usage was discontinued in 5% of patients due to severe adverse effects	2024 doi:10.1016/j.heliyon.2024.e37883
24-month-old aged CB6F1 hybrid male mi…	young mice	mean expression of Lgr5 mRNA in the stem cluster from old mice... was restored back to 87%…	2023 doi:10.1111/acel.13802
patients with T2D and metastatic lung…	those who did not take metfo…	patients treated with metformin had 20% higher survival rates than those who did not take…	2022 doi:10.3892/or.2022.8266
patients with T2D with inadequate glyc…	—	least-squares mean change from baseline in HbA1c was -1.02% (-1.11, -0.93) in the dorzagli…	2022 doi:10.1038/s41591-022-01803-5
sepsis patients with type 2 diabetes,…	—	21.9% (418/1,907) for non-metformin users	2021 doi:10.3389/fmed.2021.640785
nondiabetic patients with advanced-sta…	historical controls	relapse-free survival at 18 months of 59.3% (95% CI 38.6-70.5)	2020 doi:10.1172/jci.insight.133247
patients with type 2 diabetes under me…	before and after treatment	vaspin, irisin, QUICKI, and eGDR (ACC = 86 [%]);	2020 doi:10.3390/biom10091304
hospitalized COVID-19 patients with di…	no-metformin group	in-hospital mortality was significantly lower in the metformin group (3/104 (2.9%) versus…	2020 doi:10.4269/ajtmh.20-0375
pharmacies in 17 countries	—	Lowest priced generic of metformin 500 mg had the highest total mean availability (≥80%) a…	2019 doi:10.3389/fphar.2019.01375
patients with type 2 diabetes mellitus…	baseline	MRI-PDFF decreased significantly with sitagliptin (15.5% ± 5.6% to 11.7% ± 5.0%, P = 0.001…	2018 doi:10.1002/hep.30320
patients in the high Met group	—	achieved this for the high Met group after treatment, with HbA1c of 6.8%	2017 doi:10.1186/s12933-017-0607-6
genetically heterogeneous mice (ITP)	rapamycin alone (historical…	Metformin (0.1%) combined with rapamycin (14 ppm) robustly extended lifespan, suggestive o…	2016 doi:10.1111/acel.12496
1450 patients with type 2 diabetes rec…	glimepiride	HbA1c reduction at 1 year was 0.82% for canagliflozin 100 mg vs. 0.81% for glimepiride.	2016 doi:10.1681/asn.2016030278
mice on high-fat diet	without metformin	Clostridium cocleatum (0.10%±0.09%) abundances increased significantly after metformin tre…	2014 doi:10.1128/aem.01357-14
342 overweight patients with newly dia…	—	this subgroup experienced a 39% (P = 0.010) risk reduction for myocardial infarction	2011 doi:10.2337/dc10-2361
A/J mice treated with tobacco carcinog…	—	Metformin decreased tumor burden by 72%, which correlated with decreased cellular prolifer…	2010 doi:10.1158/1940-6207.capr-10-0055

Limitations

This is a scoping map of retrieved direct findings, not a meta-analysis: no pooled effect is computed, coverage is bounded by the Tier-2 corpus, and heterogeneity across rows precludes a single unified conclusion.

Scope

What is the range of reported effects across the metformin treatment literature, and how do they vary by population, comparator, and endpoint? This map catalogues the findings rather than converging them to one claim.

Search Summary

19 direct (A_core) sources were retrieved from the Tier-2 semantic corpus for this topic and lane-classified; each is cited with a resolvable identifier in the source bundle below.

Tensions and Gaps

Findings differ in population, comparator, endpoint, and effect size, so they are not directly comparable and are not pooled. Gaps remain where a population or comparator is represented by only a single source.