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Pooled review (meta-analysis)

Pooled review of 53 studies: diabetics on metformin had lower death risk than non-diabetics

Campbell and colleagues · Ageing research reviews · 2017

Original title: Metformin reduces all-cause mortality and diseases of ageing independent of its effect on diabetes control: A systematic review and meta-analysis.

Under review. A person has not yet checked this summary against the paper. It is written from the PubMed abstract. Until a person checks it, search engines are asked not to list this page.

What the study found

Points to benefit

Diabetics on metformin had lower all-cause death than non-diabetics (HR=0.93, 95%CI 0.88-0.99) and than diabetics on other drugs (HR=0.72, 95%CI 0.65-0.80). Cancer was lower than in non-diabetics (rate ratio=0.94, 95%CI 0.92-0.97).

The study at a glance

Type of study
Pooled review (meta-analysis)
Who or what was studied
53 studies · Mostly people with diabetes taking metformin, compared with people without diabetes or with diabetes on other drugs
What was tested
Metformin use vs no diabetes, or vs other diabetes drugs, for death and age-related disease
What it measured
The question itself: aging, frailty and death in people without diabetes
Who has a stake
No disclosure in PubMed
No disclosure in PubMed.
Journal
Ageing research reviews, 2017
Source
PubMed record 28802803. This page is based on the abstract only.

How much this study counts

  • ✓Pools the results of 53 studies.
  • •A pooled review is only as strong as the studies it pools.
  • ✓Measured the question itself: aging, frailty and death in people without diabetes.
  • •The PubMed record has no conflict-of-interest statement.
  • •Summarized from the PubMed abstract only. The full paper may hold details the abstract leaves out.

✓ Strength– Limit• Note

These points come from fixed rules about the type of study, its size and length, what it measured, and who has a stake. Every study on Digestery gets the same rules.

Where this study sits

This paper is not on the ladder. It is a pooled review (meta-analysis), and reviews and opinion pieces discuss studies that are already counted on the steps below.

↑ Stronger evidence

  1. Trials in people: aging and age-related disease

    1

    1 benefit

  2. Trials in people: other measures

    3

    2 no difference, 1 harm

  3. Trials in people: lab tests or safety

    6

    2 benefit, 2 mixed, 2 no difference

  4. Population studies

    8

    6 benefit, 2 no difference

  5. Blood levels and genes

    0

    None among the papers we read.

  6. Animals

    3

    2 benefit, 1 harm

↓ Weaker evidence

  • Points to benefit
  • Mixed
  • No difference
  • No direction
  • Points to harm

How it fits with the other research

The short answer to “Does metformin slow aging in people without diabetes?”

Not shown in people without diabetes.

Confidence: low. Based on 26 on-topic papers.

Read the full answer
  • Quoted in “What we found”: A review of 53 studies found people with diabetes on metformin died slightly less often than people without diabetes (hazard ratio 0.93). These studies show links, not causes.
  • Part of the finding “Fewer deaths seen only in people with diabetes”.
  • Summed up in “What reviews found”: Included 53 of 260 studies read in full, comparing metformin users with diabetes to others. Users had lower death rates than people without diabetes (HR 0.93) and than diabetics on other drugs (HR 0.72). Group differences could bias this.
  • Marked as a key paper in the research timeline: Review links metformin users to fewer deaths.

Other reviews on this question

See all 26 studies on this question

How this page was made

Label

First read of the abstract
Claude Sonnet
Independent second read
Claude Haiku
Differences settled
The two reads agreed on every checked field. Claude Opus 5.5.
Headline
Claude Sonnet, from the checked study record. A script checked its numbers and wording.
Numbers
Checked against the abstract by a script
“How much this study counts”
Fixed rules, the same for every study
Source check by a person
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