Randomised controlled trialcited by the Tayebat archivefull text checked★ key study A-ODD-17 in-depth review
Very aggressive blood sugar lowering in high-risk type 2 diabetes
Effects of intensive glucose lowering in type 2 diabetes.
Overview
Action to Control Cardiovascular Risk in Diabetes Study Group; Gerstein HC et al.. N Engl J Med 2008 · PMID 18539917 · DOI 10.1056/NEJMoa0802743
Pushing HbA1c below 6% increased deaths by about one-fifth and did not reduce heart attacks or strokes significantly.
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?
Does targeting a normal HbA1c (<6.0%) reduce cardiovascular events in type 2 diabetes with high cardiovascular risk?
- How was the study done?
Multicentre randomised controlled trial (open-label treatment strategies), mean 3.5 years of intensive therapy
- How many people, animals or samples were studied?
10,251; Type 2 diabetes, mean age 62.2, median HbA1c 8.1%, established CVD or additional risk factors
- What was actually found?
More deaths (HR 1.22) and more severe hypoglycaemia with intensive therapy; primary CV outcome not significantly reduced.
- How large was the observed effect?
HR 1.22 (1.01-1.46) all-cause death; HR 0.90 (0.78-1.04) primary outcome
- What do the results mean in everyday life?
Very strict sugar targets are not good for everyone, especially older people with heart disease.
- What are the study's limitations?
Strategy trial: cannot attribute harm to a specific drug; Intensive arm stopped early; High-risk population; not generalisable to early diabetes
- What does it say about Elawady's specific claim?
Core evidence that near-normal HbA1c targets can harm high-risk type 2 patients (C-INS-04).
- Do the results apply to Germany and Europe?
Multinational/US/UK/European data; directly transferable to Germany/EU clinical practice.
- What can explicitly not be concluded from this study?
That insulin specifically caused the deaths, or that lowering high glucose to moderate targets is harmful.
Scientific in-depth review
1. Full reference
- Authors
- Action to Control Cardiovascular Risk in Diabetes Study Group, Gerstein HC, Miller ME, Byington RP, Goff DC, Bigger JT, Buse JB, Cushman WC, Genuth S, Ismail-Beigi F, Grimm RH, Probstfield JL, Simons-Morton DG, Friedewald WT
- Journal
- N Engl J Med
- Year
- 2008
- Identifier
- PMID 18539917 DOI 10.1056/NEJMoa0802743 · PMC4551392
- Verification
- verified – PubMed E-utilities efetch, 2026-10-25
- Retracted
- no
- Corrections
- none
- Extent checked
- full text
- Conflicts of interest and funding
NHLBI-funded (grants NHLBI, NINR); individual COI not in abstract.
2. Research question
Does targeting a normal HbA1c (<6.0%) reduce cardiovascular events in type 2 diabetes with high cardiovascular risk?
3. Study design and population
- Study design
- Randomised controlled trial – Multicentre randomised controlled trial (open-label treatment strategies), mean 3.5 years of intensive therapy
- Population
Type 2 diabetes, mean age 62.2, median HbA1c 8.1%, established CVD or additional risk factors
- Country
USA and Canada
- Period
2001-2008
- Sample size
10,251
- Inclusion and exclusion criteria
HbA1c >=7.5%; age 40-79 with CVD or 55-79 with subclinical disease or >=2 risk factors.
4. Methods and endpoints
- Exposure / intervention
Intensive glycaemic therapy targeting HbA1c <6.0% (multiple drugs incl. insulin)
- Comparator
Standard therapy targeting HbA1c 7.0-7.9%
- Endpoints
Primary: nonfatal MI, nonfatal stroke or CV death; secondary incl. all-cause mortality
- Statistical methods
Cox proportional hazards, intention to treat
5. Actual results
- Results
HbA1c at 1 year 6.4% vs 7.5%. Primary outcome 352 vs 371 (HR 0.90, 95% CI 0.78-1.04; P=0.16). Deaths 257 vs 203 (HR 1.22, 95% CI 1.01-1.46; P=0.04). Hypoglycaemia requiring assistance and weight gain >10 kg more frequent with intensive therapy (P<0.001). Full text (PMC): CV death HR 1.35 (1.04-1.76).
- Absolute risks
Deaths 257/5128 vs 203/5123 (about 5.0% vs 4.0% over the trial; computed from reported counts and full-text group sizes).
- Authors' conclusion
Targeting normal HbA1c for 3.5 years increased mortality and did not significantly reduce major cardiovascular events; a previously unrecognised harm of intensive glucose lowering in high-risk type 2 patients.
6. Strengths
- Large RCT with hard endpoints
- Independent public funding
- Adjudicated outcomes
7. Weaknesses
- Strategy trial: cannot attribute harm to a specific drug
- Intensive arm stopped early
- High-risk population; not generalisable to early diabetes
8. Risk of bias
- Orienting tool
- RoB 2
- Type of assessment
- simplified assessment (abstract only)
- Full formal assessment
- no
- Overall risk of bias
- low
- Rationale
Open-label treatment but objective mortality endpoint; randomisation and analysis appropriate.
9. Assessment of the statistical interpretation
Mortality excess is statistically significant but borderline (lower CI 1.01); absolute difference about 1 percentage point. Primary endpoint not significantly reduced.
10. Relevance to the specific claim
Core evidence that near-normal HbA1c targets can harm high-risk type 2 patients (C-INS-04).
11. Independent contrary findings
ADVANCE (I-INS-01) and UKPDS (I-INS-02) show benefits of less extreme intensive control; Bonds (A-INS-14) shows hypoglycaemia did not explain the mortality difference.
12. Transferability to Germany and Europe
Multinational/US/UK/European data; directly transferable to Germany/EU clinical practice.
13. Overall methodological judgement
High-quality RCT, correctly quoted by the archive. Supports individualised moderate targets, not avoidance of glucose-lowering therapy.
| Multidimensional assessment | |
|---|---|
| Authenticity of the source | verified |
| Methodological quality | high |
| Risk of bias | low |
| Precision of results | moderate |
| Directness | direct |
| Reproducibility | partly replicated |
| Consistency with the overall evidence | mixed |
| Regional transferability | high |
| Adequacy of the interpretation (by the archive) | essentially correct but incomplete |
14. Open questions
Mechanism of excess mortality remains unexplained.
15. Linked fact checks
Use by the Tayebat archive
Note: according to the archive, the studies were compiled by the archive operators. Whether Dr. Elawady himself cited this study is not established.
- What the archive says about the study
ACCORD on 10,251 patients: intensive lowering with combined drugs raised total mortality (HR 1.22) and cardiovascular mortality (HR 1.35); trial stopped early; severe hypoglycaemia and weight gain linked.
- A. What was actually studied?
Does targeting a normal HbA1c (<6.0%) reduce cardiovascular events in type 2 diabetes with high cardiovascular risk?
- B. What did the authors find?
More deaths (HR 1.22) and more severe hypoglycaemia with intensive therapy; primary CV outcome not significantly reduced.
- C. What conclusions do the authors themselves draw?
Targeting normal HbA1c for 3.5 years increased mortality and did not significantly reduce major cardiovascular events; a previously unrecognised harm of intensive glucose lowering in high-risk type 2 patients.
- D. What does the archive derive from it?
Used as 'the field's own warning that lower the number at any cost is itself a documented harm'.
- E. Is this derivation scientifically justified?
Justified for near-normal targets in high-risk patients; CV death HR 1.35 confirmed in full text. Not a justification for rejecting glucose-lowering drugs.
- Adequacy of the interpretation (by the archive)
- essentially correct but incomplete