Meta-analysisindependent cross-checkabstract checked★ key study I-ODD-108 in-depth review
Very tight sugar control: fewer heart attacks, more severe low sugars
Intensive glucose control and macrovascular outcomes in type 2 diabetes.
Overview
Control Group (Turnbull FM et al.). Diabetologia 2009 · PMID 19655124 · DOI 10.1007/s00125-009-1470-0
MI -15%, major hypoglycaemia about 2.5 times more frequent; death unchanged.
Does the study support the specific claim? Partly · Methodological quality: high
Plain-language summary
Study explained simply
- What did the researchers want to find out?
Pool trials of intensive vs standard glucose control.
- How was the study done?
Pre-planned meta-analysis.
- How many people, animals or samples were studied?
27,049 people.
- What was actually found?
Modest MACE reduction; more severe hypoglycaemia; no mortality change.
- How large was the observed effect?
MACE HR 0.91; hypoglycaemia HR 2.48.
- What do the results mean in everyday life?
Over-treating sugar has a real cost; targets should be individual.
- What are the study's limitations?
Older drug strategies.
- What does it say about Elawady's specific claim?
Supports only the hypoglycaemia kernel.
- Do the results apply to Germany and Europe?
High.
- What can explicitly not be concluded from this study?
That glucose-lowering drugs starve cells in general.
Scientific in-depth review
1. Full reference
- Authors
- Control Group (Turnbull FM et al.)
- Journal
- Diabetologia
- Year
- 2009
- Identifier
- PMID 19655124 DOI 10.1007/s00125-009-1470-0
- Verification
- verified – PubMed efetch 2026-10-26; Crossref works API 2026-10-26
- Retracted
- no
- Corrections
Erratum published (Diabetologia 2009;52:2470, doi 10.1007/s00125-009-1505-6); content of erratum not reviewed.
- Extent checked
- abstract only
- Conflicts of interest and funding
Not stated in abstract (non-US government support listed in PubMed).
2. Research question
Does more intensive glucose control reduce major cardiovascular events in type 2 diabetes, and at what cost in hypoglycaemia?
3. Study design and population
- Study design
- Meta-analysis – Prospectively planned group-level meta-analysis of large RCTs of more vs less intensive glucose control (individual trials not named in the abstract)
- Population
Participants with type 2 diabetes in large glucose-lowering trials
- Country
International
- Period
Trials to 2009; mean follow-up 4.4 years
- Sample size
27,049 participants; 2,370 major vascular events
- Inclusion and exclusion criteria
Pre-specified trials of intensive vs standard glucose control
4. Methods and endpoints
- Exposure / intervention
More-intensive glucose lowering (mainly insulin, sulfonylureas and other older drugs)
- Comparator
Less-intensive control
- Endpoints
Major cardiovascular events, MI, stroke, death, major hypoglycaemia
- Statistical methods
Pre-specified meta-analysis; hazard ratios
5. Actual results
- Results
Major cardiovascular events HR 0.91 (0.84-0.99); MI HR 0.85 (0.76-0.94). All-cause mortality HR 1.04 (0.90-1.20); CV death HR 1.10 (0.84-1.42). Major hypoglycaemia HR 2.48 (1.91-3.21). Possible differential effect: no benefit in people with prior macrovascular disease (HR 1.00) vs benefit without (HR 0.84), interaction p=0.04.
- Absolute risks
Not reported in abstract.
- Authors' conclusion
More-intensive glucose lowering modestly reduced major macrovascular events and increased major hypoglycaemia; regimens should be tailored.
6. Strengths
- Pre-specified protocol
- Large number of events
7. Weaknesses
- Group-level data
- Trials used older drug strategies
- Subgroup finding exploratory
8. Risk of bias
- Orienting tool
- AMSTAR 2
- Type of assessment
- simplified assessment (abstract only)
- Full formal assessment
- no
- Overall risk of bias
- low
- Rationale
Prospectively planned; constituent RCTs at low risk of bias.
9. Assessment of the statistical interpretation
CIs log-symmetric (stats/C-ODD-03.py). The doubling of severe hypoglycaemia is precise; mortality neutral overall but ACCORD alone showed harm.
10. Relevance to the specific claim
Shows the true kernel of C-ODD-03: pushing glucose very low with older drugs causes more severe hypoglycaemia; but it does not produce a general 'famine' and net mortality was neutral while MI fell.
11. Independent contrary findings
DCCT/EDIC (I-ODD-109) and UKPDS follow-up (I-INS-02) show long-term benefits of glucose lowering.
12. Transferability to Germany and Europe
High.
13. Overall methodological judgement
Balanced evidence: intensive targets trade fewer MIs for more severe hypoglycaemia.
| Multidimensional assessment | |
|---|---|
| Authenticity of the source | verified |
| Methodological quality | high |
| Risk of bias | low |
| Precision of results | high |
| Directness | indirect |
| Reproducibility | replicated |
| Consistency with the overall evidence | consistent |
| Regional transferability | high |
| Adequacy of the interpretation (by the archive) | not applicable |
14. Open questions
Whether harms apply to modern drugs that do not cause hypoglycaemia (they generally do not).
15. Linked fact checks
- Insulin and diabetes drugs pull glucose out of the blood and out of the cells, producing an internal 'famine'. – Studies with mixed or unclear results