Severe hypoglycaemia in ADVANCE

Overview

Zoungas S et al.. N Engl J Med 2010 · PMID 20925543 · DOI 10.1056/NEJMoa1003795

Severe low-sugar episodes were followed by more heart events and deaths, probably partly because frail people get them.

Does the study support the specific claim? Partly · Methodological quality: moderate

Original publication

Plain-language summary

Scientific in-depth review

1. Full reference

Authors

Zoungas S, Patel A, Chalmers J, de Galan BE, Li Q, Billot L, Woodward M, Ninomiya T, Neal B, MacMahon S, Grobbee DE, Kengne AP, Marre M, Heller S, ADVANCE Collaborative Group

Journal

N Engl J Med

Year

2010

Identifier

PMID 20925543 DOI 10.1056/NEJMoa1003795

Verification

verified – PubMed E-utilities efetch, 2026-10-25

Retracted

no

Corrections

none

Extent checked

full text

Conflicts of interest and funding

Supported by Servier (manufacturer of gliclazide MR and perindopril-indapamide) and the National Health and Medical Research Council of Australia; individual disclosures only in online forms (not in the full text).

2. Research question

Severe hypoglycaemia and vascular events/death

3. Study design and population

Study design

Cohort study – Post hoc cohort analysis of the ADVANCE factorial RCT (NCT00145925; open-label intensive gliclazide-MR-based glucose control vs standard control), with severe hypoglycaemia as time-dependent exposure.

Population

Patients aged >=55 with type 2 diabetes diagnosed after age 30 and macro-/microvascular disease or >=1 CV risk factor; patients with a clear indication for long-term insulin at baseline were ineligible; intensive arm used modified-release gliclazide (a sulfonylurea) plus other drugs as required (target HbA1c <=6.5%).

Country

215 centres in 20 countries

Period

Recruitment June 2001 - March 2003; median follow-up 5 years.

Sample size

11,140 (intensive 5,571; standard 5,569); 231 (2.1%) with >=1 severe hypoglycaemia (150 intensive, 81 standard; 299 events); 4,975 (44.7%) with minor hypoglycaemia; 1,031 deaths (45 after severe hypoglycaemia).

Inclusion and exclusion criteria

As described in the abstract; details not available in abstract.

4. Methods and endpoints

Exposure / intervention

Severe hypoglycaemia (glucose <2.8 mmol/L or typical symptoms, with transient CNS dysfunction requiring help from another person), exposure from first episode onwards.

Comparator

No severe hypoglycaemia

Endpoints

Major macrovascular and microvascular events (adjudicated, masked), death from any cause and CV death; non-vascular serious adverse events (respiratory, digestive, skin, cancer).

Statistical methods

Time-dependent Cox models adjusted for baseline and time-dependent covariates (HbA1c, BMI, creatinine, albuminuria, SBP, drug use incl. insulin); sensitivity analyses (3- and 6-month exposure windows, pooled logistic regression, adjustment for post-randomisation CV events); C statistics; results interpreted 'in light of the many comparisons'.

5. Actual results

Results

Abstract: adjusted HRs for severe hypoglycaemia - major macrovascular events 2.88 (95% CI 2.01-4.12), microvascular 1.81 (1.19-2.74), CV death 2.68 (1.72-4.19), all-cause death 2.69 (1.97-3.67). Table 3 (multiple-covariate adjusted): macrovascular 3.45 (2.34-5.08), microvascular 2.07 (1.32-3.26), all-cause death 3.30 (2.31-4.72), CV death 3.78 (2.34-6.11), non-CV death 2.86 (1.67-4.90); death within 3 months 5.86 (2.97-11.60). Unadjusted HRs markedly higher (e.g. death 4.86). Non-vascular outcomes also associated (respiratory, digestive, skin; cancer not significant after adjustment). No dose-response with repeated episodes (death OR 1.57 for one vs 1.24 for >=2 episodes). Adding further adjustment for post-randomisation CV events attenuated death OR from 2.61 to 1.34 (0.79-2.27). Median time from severe hypoglycaemia to death 1.05 years. Annual mortality with severe hypoglycaemia lower in intensive (3.6%) than standard (5.1%) arm.

Absolute risks

19.5% (45/231) of patients with severe hypoglycaemia died vs 9.0% (986/10,909) without; annual mortality 3.6% (intensive) and 5.1% (standard) with, 1.8% and 1.9% without severe hypoglycaemia.

Authors' conclusion

Severe hypoglycaemia was strongly associated with a range of adverse outcomes; no close temporal or dose-response relation; it may contribute but is just as likely a marker of vulnerability; its occurrence should prompt clinical attention.

6. Strengths

• Large RCT cohort with systematically reported and reviewed severe hypoglycaemia
• Masked adjudication of vascular outcomes and deaths
• Extensive time-dependent adjustment and sensitivity analyses; tests of specificity with non-vascular outcomes

7. Weaknesses

• Only 231 patients with severe hypoglycaemia; post hoc, non-randomised exposure
• Associations with unrelated outcomes (skin, digestive, respiratory) and absence of dose-response point to confounding/frailty (authors)
• Marked attenuation with adjustment; residual confounding likely
• Hypoglycaemia mostly occurred under sulfonylurea-based therapy in patients not on long-term insulin - not an insulin-specific study
• Abstract and Table 3 report different adjusted HRs (models not fully described in main text)
• Prior hypoglycaemia and autonomic neuropathy not recorded

8. Risk of bias

Orienting tool

ROBINS-E

Type of assessment

structured assessment based on the full text by a single reviewer (no formal double review)

Full formal assessment

no

Overall risk of bias

some concerns

Rationale

Single-reviewer ROBINS-E-oriented judgement from the full text; formal assessment needs two independent reviewers. Overall unchanged (some_concerns) for the descriptive association; for any causal inference the confounding domain is high, as the authors themselves conclude.

Full-text review (25 October 2026): Population detail (no baseline insulin, gliclazide-based intensive arm), event counts, Table 3 adjusted HRs (differ from abstract), 3/6-month windows, attenuation after post-randomisation CV adjustment (OR 1.34), absolute death proportions and annual mortality added; Servier funding noted as gliclazide manufacturer; ROBINS-E domains added, overall unchanged.

9. Assessment of the statistical interpretation

Strong but non-specific associations (also with skin, digestive and respiratory disease), no dose-response, and attenuation to non-significance (OR 1.34) after accounting for post-randomisation CV events: severe hypoglycaemia is best read as a marker of vulnerability. Intensive control in ADVANCE did not increase mortality.

10. Relevance to the specific claim

Supports the hypoglycaemia-mortality association in C-INS-04; does not support the mechanistic claims C-INS-02, C-INS-09 and C-ODD-03.

11. Independent contrary findings

12. Transferability to Germany and Europe

Multinational/US/UK/European data; directly transferable to Germany/EU clinical practice.

13. Overall methodological judgement

Severe hypoglycaemia identifies patients at markedly higher risk and should be avoided, but this sulfonylurea-based trial cohort does not show that hypoglycaemia or insulin causes vascular events or death, and provides no support for mechanistic claims about insulin 'starving' cells.

14. Open questions

None beyond those stated.

15. Linked fact checks

• Injected insulin halts the Krebs cycle, blocks protein and DNA synthesis, starves the brain of glucose and causes seizures and blood clots. – Studies with mixed or unclear results
• Large trials in type 2 diabetes showed that intensive glucose lowering towards normal HbA1c can be harmful: ACCORD was stopped after intensive therapy raised all-cause mortality by 22%, and severe hypoglycaemia was associated with roughly doubled mortality. – Studies supporting the claim
• Insulin is not needed for glucose to enter cells (the HbA1c inside red blood cells proves it); insulin therefore does not treat diabetes but 'starves' cells, especially the brain, of sugar. – Studies with mixed or unclear results
• 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

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

Listed in the archive bibliography for 'insulin-injections' without its own interpretation; used as general support for the claim that insulin intensification harms.

A. What was actually studied?

Severe hypoglycaemia and vascular events/death

B. What did the authors find?

Adjusted HR for death 2.69 (abstract; 3.30 in Table 3) after severe hypoglycaemia in 231 patients; similar associations with non-vascular conditions; no dose-response; hypoglycaemia 'just as likely' a marker of vulnerability; intensive therapy was gliclazide-based and long-term insulin users were excluded at entry.

C. What conclusions do the authors themselves draw?

Strong associations; hypoglycaemia may contribute, but is just as likely a marker of vulnerability.

D. What does the archive derive from it?

Supports hypoglycaemia harm.

E. Is this derivation scientifically justified?

Justified only as evidence that severe hypoglycaemia marks high risk; not as evidence that insulin causes harm (the trial's intensive regimen was sulfonylurea-based) or that hypoglycaemia is causal.

Adequacy of the interpretation (by the archive)

not applicable