Cochrane · systematic review · CD008558
Metformin for prevention or delay of type 2 diabetes mellitus and its associated complications in persons at increased risk for the development of type 2 diabetes mellitus
Madsen, KS, Chi, Y, Metzendorf, MI, et al. · Cochrane Database of Systematic Reviews · 2019 · Cochrane Library
Metabolic and Endocrine DisordersAMSTAR 2: not assessed
SoF tableOnly the outcomes this review put in its Summary of Findings table are listed (the Cochrane Handbook caps them at about seven per comparison). Its other analyses are not shown here.
Questions
29
current version
GRADE rated
18
No studies
11
Included studies
NR
No studies 11 · 37.9%Ungraded 0 · 0%Very low 12 · 41.4%Low 4 · 13.8%Moderate 2 · 6.9%High 0 · 0%
Ungraded means an effect was reported without a GRADE rating; it is not a gap. No studies means the review found nothing to answer the question. The six categories are a display order, not a score.
Questions and results
Summary of findings table for metformin compared with diet and exercise or another antidiabetic drug
Population: people at increased risk for developing type 2 diabetes
| Outcome | Effect | Evidence | Status / GRADE |
|---|---|---|---|
All‐cause mortality (N) Summary of findings table for metformin vs diet and exercise or another antidiabetic drug | no estimate extracted | NR | No studies |
Placebo or diet and exercise Summary of findings table for metformin vs diet and exercise or another antidiabetic drug | RR 1.11 [0.41, 3.01] | 5 studies · 2833 participants | Very low Downgraded: risk of bias, imprecision, inconsistency |
Intensive diet plus exercise Summary of findings table for metformin vs diet and exercise or another antidiabetic drug | RR 1.61 [0.5, 5.23] | 4 studies · 2550 participants | Very low Downgraded: risk of bias, imprecision, inconsistency |
Sulphonylurea Summary of findings table for metformin vs diet and exercise or another antidiabetic drug | no estimate extracted | NR | No studies |
Acarbose Summary of findings table for metformin vs diet and exercise or another antidiabetic drug | no estimate extracted | 1 study · 89 participants | Very low Downgraded: risk of bias, imprecision, inconsistency |
Thiazolidinediones Summary of findings table for metformin vs diet and exercise or another antidiabetic drug | no estimate extracted | NR | No studies |
Placebo or diet and exercise Diagnostic criteria: 3 trials applied the WHO 1985 criteria (FPG <7.8 mmol/L and 2‐hour glucose ≥7.8 mmol/L and <11.1 mmol/L after a 75 g OGTT) (Fang 2004; Li 1999; Lu 2002). 5 trials applied the WHO 1999 criteria (FPG... Summary of findings table for metformin vs diet and exercise or another antidiabetic drug | RR 0.5 [0.38, 0.65] | 12 studies · 3632 participants | Moderate Downgraded: risk of bias, imprecision, inconsistency |
Intensive diet plus exercise Diagnostic criteria: 1 trial applied the WHO 1985 criteria (FPG < 7.8 mmol/L and 2‐hour glucose ≥ 7.8 mmol/L and < 11.1 mmol/L) (Fang 2004) Summary of findings table for metformin vs diet and exercise or another antidiabetic drug | RR 0.8 [0.47, 1.37] | 7 studies · 2960 participants | Moderate Downgraded: risk of bias, imprecision, inconsistency |
Acarbose Diagnostic criteria: 1 trial applied the WHO 1985 criteria (FPG < 7.8 mmol/L and 2‐hour glucose ≥ 7.8 mmol/L and < 11.1 mmol/L) (Fang 2004). 1 trial applied the WHO 1999 criteria (FPG ≥ 7.0 mmol/L and/or a 2‐hpur glucose ≥ 11.1 mmol/L aft... Summary of findings table for metformin vs diet and exercise or another antidiabetic drug | RR 1.72 [0.72, 4.14] | 3 studies · 295 participants | Low Downgraded: risk of bias, imprecision, inconsistency |
Thiazolidinediones Diagnostic criteria: 2 trials applied the WHO 1999 criteria (FPG ≥ 7.0 mmol/L and/or a 2‐hour glucose ≥ 11.1 mmol/L after a 75 g OGTT) (Jin 2009; Zeng 2013). No medical association recommended the cut‐off points applied in Maji ... Summary of findings table for metformin vs diet and exercise or another antidiabetic drug | RR 0.99 [0.41, 2.4] | 3 studies · 320 participants | Low Downgraded: risk of bias, imprecision, inconsistency |
Intensive diet plus exercises Summary of findings table for metformin vs diet and exercise or another antidiabetic drug | no estimate extracted | 2 studies · 139 participants | Very low Downgraded: risk of bias, imprecision, inconsistency |
Acarbose Summary of findings table for metformin vs diet and exercise or another antidiabetic drug | no estimate extracted | 1 study · 101 participants | Very low Downgraded: risk of bias, imprecision, inconsistency |
Thiazolidinediones Summary of findings table for metformin vs diet and exercise or another antidiabetic drug | no estimate extracted | 1 study · 86 participants | Very low Downgraded: risk of bias, imprecision, inconsistency |
Cardiovascular mortality Summary of findings table for metformin vs diet and exercise or another antidiabetic drug | no estimate extracted | NR | No studies |
Placebo or diet and exercise Summary of findings table for metformin vs diet and exercise or another antidiabetic drug | no estimate extracted | 2 studies · 2416 participants | Very low Downgraded: risk of bias, imprecision, inconsistency |
Intensive diet plus exercise Summary of findings table for metformin vs diet and exercise or another antidiabetic drug | no estimate extracted | 2 studies · 2400 participants | Very low Downgraded: risk of bias, imprecision, inconsistency |
Acarbose Summary of findings table for metformin vs diet and exercise or another antidiabetic drug | no estimate extracted | NR | No studies |
Placebo or diet and exercise Description: SF‐36 to evaluate the health utility index SF‐6D (physical component summaries and mental component summaries) Minimal important difference: difference in scores between groups of at least 3% Summary of findings table for metformin vs diet and exercise or another antidiabetic drug | no estimate extracted | 1 study · 2144 participants | Very low Downgraded: risk of bias, imprecision, inconsistency |
Intensive diet plus exercise Summary of findings table for metformin vs diet and exercise or another antidiabetic drug | no estimate extracted | NR | No studies |
Socioeconomic effects Summary of findings table for metformin vs diet and exercise or another antidiabetic drug | no estimate extracted | NR | No studies |
Placebo or diet and exercise Description: direct medical costs Summary of findings table for metformin vs diet and exercise or another antidiabetic drug | no estimate extracted | 2 studies · 2416 participants | Low Downgraded: risk of bias, imprecision, inconsistency |
Intensive diet plus exercise Description: direct medical costs per participant Summary of findings table for metformin vs diet and exercise or another antidiabetic drug | no estimate extracted | 2 studies · 2400 participants | Low Downgraded: risk of bias, imprecision, inconsistency |
Summary of findings table for metformin plus intensive diet and exercise compared with intensive diet and exercise
Population: people at increased risk for developing type 2 diabetes
| Outcome | Effect | Evidence | Status / GRADE |
|---|---|---|---|
All‐cause mortality (N) Summary of findings table for metformin plus intensive diet and exercise vs intensive diet and exercise | no estimate extracted | 2 studies · 450 participants | Very low Downgraded: risk of bias, imprecision, inconsistency |
Incidence of type 2 diabetes mellitus (N) Diagnostic criteria: 2 trials applied the WHO 1999 criteria (FPG ≥7.0 mmol/L and/or a 2‐hour glucose ≥11.1 mmol/L after a 75 g OGTT) (IDPP‐1 2006; Zhao 2013) Summary of findings table for metformin plus intensive diet and exercise vs intensive diet and exercise | RR 0.55 [0.1, 2.92] | 2 studies · 332 participants | Very low Downgraded: risk of bias, imprecision, inconsistency |
Serious adverse events Summary of findings table for metformin plus intensive diet and exercise vs intensive diet and exercise | no estimate extracted | NR | No studies |
Cardiovascular mortality Summary of findings table for metformin plus intensive diet and exercise vs intensive diet and exercise | no estimate extracted | NR | No studies |
Non‐fatal myocardial infarction/stroke Summary of findings table for metformin plus intensive diet and exercise vs intensive diet and exercise | no estimate extracted | NR | No studies |
Health‐related quality of life Summary of findings table for metformin plus intensive diet and exercise vs intensive diet and exercise | no estimate extracted | NR | No studies |
Socioeconomic effects Description: direct medical costs per participant Summary of findings table for metformin plus intensive diet and exercise vs intensive diet and exercise | no estimate extracted | 1 study · 94 participants | Very low Downgraded: risk of bias, imprecision, inconsistency |