Systematic reviewindependent cross-checkabstract only checked★ key study I-ODD-08 in-depth review

Metformin and lactic acidosis: Cochrane review

Risk of fatal and nonfatal lactic acidosis with metformin use in type 2 diabetes mellitus.

Overview

Salpeter SR et al.. Cochrane Database Syst Rev 2010 · PMID 20393934 · DOI 10.1002/14651858.CD002967.pub4

No lactic acidosis cases in about 70,000 patient-years of metformin use.

Does the study support the specific claim? No · Methodological quality: high

Study explained simply

What did the researchers want to find out?: Incidence of lactic acidosis and lactate levels with metformin
How was the study done?: Cochrane systematic review of comparative trials and cohorts
How many people, animals or samples were studied?: 347 studies; 70,490 metformin vs 55,451 non-metformin patient-years; Type 2 diabetes in trials/cohorts >=1 month
What was actually found?: No cases; no lactate difference.
How large was the observed effect?: Upper limit 4.3/100,000 PY
What do the results mean in everyday life?: Metformin acid build-up is extremely rare.
What are the study's limitations?: Trials often excluded high-risk patients
What does it say about Elawady's specific claim?: Contradicts C-ODD-01.
Do the results apply to Germany and Europe?: International.
What can explicitly not be concluded from this study?: Risk in severe kidney failure.

Incidence of lactic acidosis and lactate levels with metformin

Study design: Systematic review – Cochrane systematic review of comparative trials and cohorts
Population: Type 2 diabetes in trials/cohorts >=1 month
Country: International
Period: Searched to about 2009
Sample size: 347 studies; 70,490 metformin vs 55,451 non-metformin patient-years
Inclusion and exclusion criteria: As described in the abstract; details not available in abstract.

Results: No cases of lactic acidosis in either group; upper limit of true incidence 4.3 vs 5.4 per 100,000 patient-years; no difference in lactate levels.
Absolute risks: not reported
Authors' conclusion: No evidence that metformin increases lactic acidosis or lactate vs other treatments.

Orienting tool: AMSTAR 2
Type of assessment: simplified assessment (abstract only)
Full formal assessment: no
Overall risk of bias: low
Rationale: Cochrane review; selection of low-risk patients limits generalisability.

Rare event; upper bounds very low.

Contradicts C-ODD-01.

Case reports in renal failure.

International.

Strong evidence lactic acidosis is very rare.

Multidimensional assessment
Multidimensional assessment
Authenticity of the source	verified
Methodological quality	high
Risk of bias	low
Precision of results	moderate
Directness	direct
Reproducibility	replicated
Consistency with the overall evidence	consistent
Regional transferability	high
Adequacy of the interpretation (by the archive)	not applicable

None beyond those stated.