SynthesisMedicine2020

Metformin therapy and cognitive dysfunction in patients with type 2 diabetes: A meta-analysis and systematic review.

Qing-Qing Zhang, Wen-Shan Li, Zhou Liu, Hui-Li Zhang, Ying-Gui Ba, Rui-Xia Zhang

Open access · goldAbstract readMeta-AnalysisSystematic Review
In one paragraph

Synthesis in Medicine, 2020. The graph read 7 numbers from its abstract, feeding 4 cells of the map: it . Cited by 29 papers, 3 of them syntheses that pooled it.

7numbers the graph read from it
1cell of the map it votes in
29citing papers in PubMed, 3 pooled it
3.5field-weighted citation impact, top 7% 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.

← favours the comparatorfavours the treatment →
1 · no effect
Quality of life & behaviourfavours the comparator · head-to-head · t2dfeeds one cell of the map
HR 0.710.66 to 0.76
In the subgroup analysis of various regions controlling for age, gender, education, diabetes course, complications, metformin administration and dosage, and follow-up time, metformin significantly improved cognitive dysfunction in patients in the Americas and Europe (HR 0.69; 95% CI [0.63, 0.74]), (HR 0.71; 95% CI [0.66, 0.76], respectively), while metformin did not significantly improve cognitive dysfunction in Asian patients (HR 0.99; 95% CI [0.96, 1.01]).
Quality of life & behaviourno clear difference · head-to-head · t2dfeeds one cell of the map
HR 0.990.96 to 1.01
In the subgroup analysis of various regions controlling for age, gender, education, diabetes course, complications, metformin administration and dosage, and follow-up time, metformin significantly improved cognitive dysfunction in patients in the Americas and Europe (HR 0.69; 95% CI [0.63, 0.74]), (HR 0.71; 95% CI [0.66, 0.76], respectively), while metformin did not significantly improve cognitive dysfunction in Asian patients (HR 0.99; 95% CI [0.96, 1.01]).
Quality of life & behaviourfavours the comparator · head-to-head · t2dfeeds one cell of the map
HR 0.690.63 to 0.74
In the subgroup analysis of various regions controlling for age, gender, education, diabetes course, complications, metformin administration and dosage, and follow-up time, metformin significantly improved cognitive dysfunction in patients in the Americas and Europe (HR 0.69; 95% CI [0.63, 0.74]), (HR 0.71; 95% CI [0.66, 0.76], respectively), while metformin did not significantly improve cognitive dysfunction in Asian patients (HR 0.99; 95% CI [0.96, 1.01]).

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

Quality of life & behaviourcomparator not stated · t2dfeeds one cell of the map
HR 1.341.24 to 1.43
The use of insulin aggravated cognitive dysfunction (HR 1.34; 95% CI [1.24, 1.43]).
Quality of life & behaviourcomparator not stated · t2dfeeds one cell of the map
HR 0.900.88 to 0.92
Metformin significantly reduced the occurrence of cognitive dysfunction in patients with T2D (HR 0.90; 95% CI [0.88, 0.92]).
Quality of life & behaviourcomparator not stated · t2dfeeds one cell of the map
HR 0.920.88 to 0.95
Compared with other hypoglycemic drugs, sulfonylureas also improved cognitive dysfunction (HR 0.92; 95% CI [0.88, 0.95]).
Quality of life & behaviourcomparator not stated · t2dfeeds one cell of the map
HR 0.970.87 to 1.07
Thiazolidinediones gave no statistically significant improvement in cognitive dysfunction (HR 0.97; 95% CI [0.87, 1.07]).

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×quality of life & behaviour

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

No other readable study in this cell yet. This paper is the evidence.

Belief with this paper
0.00contested · 0 families support, 1 contradict · against placebo
Without itNot a counted family in this claim, so removing it changes nothing.

Insulin×quality of life & behaviour

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

4 readable studies in this cell: 1 favour the treatment, 2 find no difference, 1 favour the comparator.

Belief with this paper
0.25no deciding trial · 0 families support, 0 contradict · against placebo
Without itNot a counted family in this claim, so removing it changes nothing.
← favours the treatmentfavours the comparator →
0 · no effect
NCT038829701,444 enrolled · 2019
Δ -0.26-0.57 to 0.05
NCT045379231,428 enrolled · 2020
Δ 1.500.50 to 2.60
NCT04093752917 enrolled · 2019
Δ -0.47-0.81 to -0.13
NCT00469092480 enrolled · 2007
Δ 0.04-2.40 to 2.48

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

Sulfonylureas & glinides×quality of life & behaviour

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

No other readable study in this cell yet. This paper is the evidence.

Belief with this paperNo claim has been compiled for this cell yet.

Thiazolidinediones×quality of life & behaviour

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

No other readable study in this cell yet. This paper is the evidence.

Belief with this paperNo claim has been compiled for this cell yet.
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

29 citing papers in PubMed, 3 syntheses or guidelines pooled it, 55 citations in OpenAlex.

  1. Pooled it
  2. Pooled it
  3. Pooled it
  4. Article
  5. Article
  6. Review
  7. Review
  8. Review
  9. Article
  10. Observational
  11. Review
  12. Review
  13. Review
  14. Review
  15. Review
  16. Article
  17. Review
  18. Article
  19. Insights into Cognitive Brain Health in Chronic Kidney Disease.Gerontology & geriatrics : research · 2022
    Article
  20. 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

6 authors at 3 institutions in 1 country.

Qing-Qing ZhangDepartment of Endocrinology, Qinghai University Affiliated Hospital.
Wen-Shan LiDepartment of Neurosurgery, Qinghai Provincial People's Hospital.
Zhou LiuGraduate School of Qinghai University.
Hui-Li ZhangDepartment of Endocrinology, Qinghai University Affiliated Hospital.
Ying-Gui BaDepartment of Nephrology, Qinghai University Affiliated Hospital Xining, Qinghai, China.
Rui-Xia ZhangDepartment of Endocrinology, Qinghai University Affiliated Hospital.
Qinghai University Affiliated Hospital · CNBeihai People's Hospital · CNQinghai University · CN

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.

backgroundType 2 diabetes (T2D) is a risk factor for cognitive dysfunction. The relationship between metformin therapy and cognitive function in patients with T2D is unknown. Therefore, we determined the relationship between metformin therapy and cognitive function in patients with T2D using a meta-analysis.

methodsWe systematically searched the Cochrane library, PubMed, and Embase to identify studies showing correlations, and we calculated hazard ratios (HRs).

resultsWe identified 10 studies including 254,679 participants. Metformin significantly reduced the occurrence of cognitive dysfunction in patients with T2D (HR 0.90; 95% CI [0.88, 0.92]). Compared with other hypoglycemic drugs, sulfonylureas also improved cognitive dysfunction (HR 0.92; 95% CI [0.88, 0.95]). Thiazolidinediones gave no statistically significant improvement in cognitive dysfunction (HR 0.97; 95% CI [0.87, 1.07]). The use of insulin aggravated cognitive dysfunction (HR 1.34; 95% CI [1.24, 1.43]). In the subgroup analysis of various regions controlling for age, gender, education, diabetes course, complications, metformin administration and dosage, and follow-up time, metformin significantly improved cognitive dysfunction in patients in the Americas and Europe (HR 0.69; 95% CI [0.63, 0.74]), (HR 0.71; 95% CI [0.66, 0.76], respectively), while metformin did not significantly improve cognitive dysfunction in Asian patients (HR 0.99; 95% CI [0.96, 1.01]).

conclusionsMetformin significantly improved cognitive dysfunction in patients with T2D. Sulfonylureas also improved cognitive dysfunction. Thiazolidinediones had no significant effect on cognitive dysfunction. The use of insulin aggravated cognitive dysfunction. Metformin improved cognitive dysfunction more significantly in patients in the Americas and Europe than in Asia.

Indexed as

Cognitive DysfunctionDiabetes Mellitus, Type 2HumansMetforminMetformin

Identifiers

PMID32150083
PMCPMC7478804
OpenAlexW3011428671

What OpenQuestion holds

Texttitle and abstract
LicenceCC BY-NC
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 OpenQuestion graph.