Every major class of glucose-lowering drug (metformin, sulfonylureas, thiazolidinediones, DPP-4 inhibitors, SGLT2 inhibitors, GLP-1 agonists) carries a documented signal of serious harm in the peer-reviewed literature.
Original statement
كل فئة من فئات أدوية السكري ـ من الميتفورمين والسلفونيل يوريا والثيازوليدينديونات إلى مثبطات DPP-4 و SGLT-2 وناهضات GLP-1 ـ تحمل توقيعاً موثَّقاً من الأذى الجسيم في الأدبيات الطبية الرصينة
verbatim according to source. Translation by the project; the Arabic wording is authoritative.
Translation
Every major class of glucose-lowering drug (metformin, sulfonylureas, thiazolidinediones, DPP-4 inhibitors, SGLT2 inhibitors, GLP-1 agonists) carries a documented signal of serious harm in the peer-reviewed literature.
Origin
- Source status
- Archive editors
- Attribution
- Archive editors (not Elawady)
- Origin
- https://eltayebat.com/rule/oral-diabetes-drugs/
- Attribution uncertainty
- Editorial narrative and study selection written by the archive operators.
- Claimed health effect
Heart failure, MI, amputation, Fournier gangrene, bladder cancer, B12 deficiency, NAION
- Population concerned
People with type 2 diabetes
- Geographic restriction by Elawady
none found
Scientific assessment
Mostly true – Correct at its core, but with limitations or minor inaccuracies.
Certainty of evidence: moderate – Further research may still affect the assessment.
1. What was claimed?
All drug classes have documented serious harms.
2. What is demonstrably correct?
Rosiglitazone MI OR 1.43 (A-ODD-01) and heart failure HR 2.10 (A-ODD-02, I-ODD-13); pioglitazone bladder cancer HR 1.63 (A-ODD-03); metformin B12 deficiency (A-ODD-04, A-ODD-05, A-ODD-06); sulfonylureas vs metformin aHR 1.21 (A-ODD-07); saxagliptin heart-failure hospitalisation HR 1.27 (A-ODD-08); canagliflozin amputation HR 1.97 (A-ODD-09) and fractures in CANVAS (A-ODD-13); SGLT2 DKA (A-ODD-10, A-ODD-11), confirmed in the randomised CREDENCE trial (adjudicated DKA 11 vs 1; HR 10.80, 1.39-83.65; I-ODD-05), and Fournier reports (A-ODD-12); GLP-1 pancreatitis association (A-ODD-14), GI adverse events (A-ODD-15), NAION association (A-ODD-16), and in LEADER more acute gallstone disease (3.1% vs 1.9%), acute cholecystitis (0.8% vs 0.4%) and GI-related discontinuation (9.5% vs 7.3%) with liraglutide (I-ODD-06). All numbers were checked against the abstracts or full texts and are reported accurately.
3. What is wrong or exaggerated?
The same CANVAS paper reports a 14% reduction of major cardiovascular events and possible kidney benefit (A-ODD-09); the archive mentions only the amputation finding. In CREDENCE canagliflozin reduced kidney failure and showed 'no significant differences in rates of amputation or fracture' (I-ODD-05). RECORD found rosiglitazone non-inferior for overall cardiovascular outcomes, with MI data 'inconclusive' (I-ODD-13). An RCT meta-analysis found no significant Fournier excess (I-ODD-12). Several of these drugs reduce death: empagliflozin -32% all-cause death (I-ODD-02), liraglutide HR 0.85 (I-ODD-06), dapagliflozin HR 0.69 in CKD (I-ODD-03), metformin -36% (I-ODD-01). Saxagliptin's primary ischaemic outcome was neutral (HR 1.00) (A-ODD-08). Listing harms without benefits gives a misleading net picture.
4. What remains unclear?
Some signals (NAION, pioglitazone bladder cancer, sulfonylurea cardiovascular risk) remain debated.
5. Which studies support it?
A-ODD-01 to A-ODD-16; I-ODD-05 (DKA) and I-ODD-06 (gallstone disease, cholecystitis) for the harm signals.
6. Which studies contradict it?
I-ODD-01 to I-ODD-04, I-ODD-07, I-ODD-12, I-ODD-13 (benefits or non-confirmation); I-ODD-05 and I-ODD-06 also show net benefit (kidney failure, death).
7. What applies to Germany and Europe?
European (EASD) and German (DDG) guidance follow the same evidence base as the ADA/EASD consensus: individualised HbA1c targets, insulin as mandatory therapy in type 1 diabetes, and SGLT2 inhibitors/GLP-1 receptor agonists for people with cardiovascular or kidney disease. No country-specific difference changes the assessment.
8. What is known about Egypt?
Egypt has one of the highest diabetes prevalences in the region; the same drug classes and insulins are used. Access barriers and cost may make advice to stop medication attractive, which increases the practical risk of this claim. No Egypt-specific evidence changes the assessment.
9. What practical conclusion is appropriate?
Every drug has side effects, and the archive's list is factually correct study by study. The medical question is the balance of benefit and harm for a specific person, which for several classes is clearly favourable in defined groups.
Assessment details
- Rationale for certainty of evidence
Each listed signal exists in the literature and is correctly quoted (verified for each study). However the strength differs greatly: some are confirmed in RCTs (rosiglitazone heart failure, metformin B12, canagliflozin amputation in CANVAS), some were not confirmed (canagliflozin amputation in CREDENCE, Fournier gangrene in RCT meta-analysis, rosiglitazone MI in RECORD), and the selection omits proven benefits in the same trials.
- Source quality
Archive editorial with correctly cited, selectively chosen studies.
- Regional transferability
Multinational data.
- Regional scope of the claim
- general (biological/medical)
- Last reviewed
- 25 October 2026 provisional
In plain language
The archive lists real side effects reported for every type of diabetes medicine, and its numbers are correct. But it leaves out that several of the same medicines prevent heart attacks, kidney failure and deaths in large trials, sometimes in the very same study it quotes. Some warning signs were also not confirmed later. A fair picture weighs both sides for each person.
Studies on this claim
Studies supporting the claim (16)
-
Rosiglitazone and heart attacks: pooled trials
Nissen SE et al.. N Engl J Med 2007 · PMID 17517853 · DOI 10.1056/NEJMoa072761Meta-analysiscited by the Tayebat archiveabstract only checked★ key studyPooling 42 trials suggested 43% more heart attacks; the increase in heart deaths was not statistically certain.
Does the study support the specific claim? Partly · Methodological quality: moderate · Certainty of evidence: see overall assessment of the claim
Original publication · Scientific details
Study explained simply
- What did the researchers want to find out?
Effect of rosiglitazone on MI and CV death
- How was the study done?
Meta-analysis of 42 randomised trials (fixed effects, trial-level data)
- How many people, animals or samples were studied?
42 trials (116 screened); Type 2 diabetes in trials >24 weeks, mean age 56, HbA1c 8.2%
- What was actually found?
MI OR 1.43; CV death OR 1.64 (n.s.).
- How large was the observed effect?
OR 1.43 (1.03-1.98)
- What do the results mean in everyday life?
A real warning signal that changed drug regulation.
- What are the study's limitations?
No patient-level data; Rare events, fixed-effect model; Short trials not designed for CV outcomes
- What does it say about Elawady's specific claim?
- Do the results apply to Germany and Europe?
Rosiglitazone no longer marketed in EU (not verified).
- What can explicitly not be concluded from this study?
That all diabetes drugs raise heart attacks.
-
Rosiglitazone and heart failure (RECORD)
Komajda M et al.. Eur Heart J 2010 · PMID 20118174 · DOI 10.1093/eurheartj/ehp604Randomised controlled trialcited by the Tayebat archivefull text checkedHeart failure doubled with rosiglitazone (2.6 extra cases per 1,000 patient-years), but overall heart deaths did not increase.
Does the study support the specific claim? Yes · Methodological quality: high · Certainty of evidence: see overall assessment of the claim
Original publication · Scientific details
Study explained simply
- What did the researchers want to find out?
Heart failure risk with rosiglitazone
- How was the study done?
Analysis of heart failure events in an open-label RCT (RECORD)
- How many people, animals or samples were studied?
4,447; Type 2 diabetes on metformin or SU, HbA1c 7.9%
- What was actually found?
HF HR 2.10.
- How large was the observed effect?
HR 2.10 (1.35-3.27)
- What do the results mean in everyday life?
Avoid in heart failure.
- What are the study's limitations?
Open-label; sponsored and analysed by the manufacturer (GSK); relatively few HF events (90).
- What does it say about Elawady's specific claim?
Supports C-ODD-09.
- Do the results apply to Germany and Europe?
European trial.
- What can explicitly not be concluded from this study?
Increased overall CV mortality.
-
Pioglitazone and bladder cancer
Tuccori M et al.. BMJ 2016 · PMID 27029385 · DOI 10.1136/bmj.i1541Cohort studycited by the Tayebat archivefull text checkedPioglitazone users had 63% more bladder cancer, about 3 extra cases per 10,000 people per year.
Does the study support the specific claim? Yes · Methodological quality: moderate · Certainty of evidence: see overall assessment of the claim
Original publication · Scientific details
Study explained simply
- What did the researchers want to find out?
Pioglitazone and bladder cancer
- How was the study done?
Population-based cohort (CPRD), time-varying lagged exposure
- How many people, animals or samples were studied?
145,806; New users of antidiabetic drugs
- What was actually found?
HR 1.63 with dose/duration response.
- How large was the observed effect?
HR 1.63 (1.22-2.19)
- What do the results mean in everyday life?
Small absolute risk to consider.
- What are the study's limitations?
Observational; only 54 bladder cancers in pioglitazone users; possible residual confounding or detection (more urine tests).
- What does it say about Elawady's specific claim?
- Do the results apply to Germany and Europe?
UK data.
- What can explicitly not be concluded from this study?
Certain causation.
-
Metformin and vitamin B12
de Jager J et al.. BMJ 2010 · PMID 20488910 · DOI 10.1136/bmj.c2181Randomised controlled trialcited by the Tayebat archivefull text checked★ key studyOver 4 years metformin lowered B12 by 19%, causing deficiency in about 1 of every 14 users.
Does the study support the specific claim? Yes · Methodological quality: high · Certainty of evidence: see overall assessment of the claim
Original publication · Scientific details
Study explained simply
- What did the researchers want to find out?
Metformin and vitamin B12 deficiency
- How was the study done?
Multicentre double-blind placebo-controlled RCT (HOME trial follow-up)
- How many people, animals or samples were studied?
390; Type 2 diabetes treated with insulin
- What was actually found?
B12 -19%; NNH 13.8.
- How large was the observed effect?
-19% B12; +7.2 pp deficiency
- What do the results mean in everyday life?
Check B12 regularly on metformin.
- What are the study's limitations?
Secondary analysis; groups differed in age and smoking at baseline; one third without final blood sample; only blood levels, no clinical symptoms measured; insulin-treated patients.
- What does it say about Elawady's specific claim?
Supports C-ODD-07.
- Do the results apply to Germany and Europe?
Dutch data.
- What can explicitly not be concluded from this study?
That metformin is net harmful.
-
Metformin and B12 in US survey
Reinstatler L et al.. Diabetes Care 2012 · PMID 22179958 · DOI 10.2337/dc11-1582Cross-sectional studycited by the Tayebat archivefull text checked5.8% of metformin users had B12 deficiency vs 2.4% of other diabetics.
Does the study support the specific claim? Yes · Methodological quality: moderate · Certainty of evidence: see overall assessment of the claim
Original publication · Scientific details
Study explained simply
- What did the researchers want to find out?
B12 deficiency prevalence with metformin; effect of supplements
- How was the study done?
Cross-sectional survey (NHANES)
- How many people, animals or samples were studied?
8,488 (1,621 with T2D + 6,867 without); US adults >=50 with/without type 2 diabetes
- What was actually found?
aOR 2.92.
- How large was the observed effect?
aOR 2.92 (1.26-6.78)
- What do the results mean in everyday life?
Consistent B12 effect.
- What are the study's limitations?
Snapshot survey (no time sequence); no duration-response; smoking/alcohol not adjusted; small inconsistencies between abstract and results; blood levels only.
- What does it say about Elawady's specific claim?
Supports C-ODD-07.
- Do the results apply to Germany and Europe?
US data.
- What can explicitly not be concluded from this study?
Causation alone.
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Metformin and B12 over 13 years
Aroda VR et al.. J Clin Endocrinol Metab 2016 · PMID 26900641 · DOI 10.1210/jc.2015-3754Randomised controlled trialcited by the Tayebat archiveabstract only checkedEach year of metformin raised the odds of B12 deficiency by about 13%.
Does the study support the specific claim? Yes · Methodological quality: moderate · Certainty of evidence: see overall assessment of the claim
Original publication · Scientific details
Study explained simply
- What did the researchers want to find out?
Long-term metformin and B12 deficiency
- How was the study done?
Secondary analysis of RCT and open-label extension (DPP/DPPOS)
- How many people, animals or samples were studied?
2,155 randomised (1,082 + 1,073); B12 measured in 1,715 at 5 years and 1,520 at 13 years; People with prediabetes and overweight
- What was actually found?
OR 1.13 per year.
- How large was the observed effect?
OR 1.13 (1.06-1.20)
- What do the results mean in everyday life?
Monitor B12.
- What are the study's limitations?
Placebo group partly unblinded after DPP; Secondary analysis
- What does it say about Elawady's specific claim?
Supports C-ODD-07.
- Do the results apply to Germany and Europe?
US data.
- What can explicitly not be concluded from this study?
Clinical harm magnitude.
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Sulfonylurea vs metformin as first drug
Roumie CL et al.. Ann Intern Med 2012 · PMID 23128859 · DOI 10.7326/0003-4819-157-9-201211060-00003Cohort studycited by the Tayebat archivefull text checked★ key studyStarting a sulfonylurea instead of metformin was linked to about 1-4 extra heart events or deaths per 1,000 people per year.
Does the study support the specific claim? Partly · Methodological quality: moderate · Certainty of evidence: see overall assessment of the claim
Original publication · Scientific details
Study explained simply
- What did the researchers want to find out?
Sulfonylurea vs metformin monotherapy on CVD events/death
- How was the study done?
Retrospective cohort (VHA + Medicare) with propensity-matched sensitivity analysis
- How many people, animals or samples were studied?
253,690; Veterans initiating metformin or SU, excluding CKD and serious illness
- What was actually found?
aHR 1.21.
- How large was the observed effect?
aHR 1.21 (1.13-1.30)
- What do the results mean in everyday life?
Metformin is preferred first-line.
- What are the study's limitations?
Observational; mostly white men; under 1 year median follow-up; many stopped treatment; possible residual confounding.
- What does it say about Elawady's specific claim?
Supports C-ODD-11.
- Do the results apply to Germany and Europe?
US veterans.
- What can explicitly not be concluded from this study?
That sulfonylureas cause death.
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Saxagliptin heart safety trial
Scirica BM et al.. N Engl J Med 2013 · PMID 23992601 · DOI 10.1056/NEJMoa1307684Randomised controlled trialcited by the Tayebat archiveabstract only checkedNo effect on heart attacks or strokes, but more heart failure hospitalisations (3.5% vs 2.8%, i.e. 0.7 percentage points).
Does the study support the specific claim? Partly · Methodological quality: high · Certainty of evidence: see overall assessment of the claim
Original publication · Scientific details
Study explained simply
- What did the researchers want to find out?
CV safety/efficacy of saxagliptin
- How was the study done?
Double-blind placebo-controlled CV outcome RCT (SAVOR-TIMI 53)
- How many people, animals or samples were studied?
16,492; Type 2 diabetes with or at risk for CV events
- What was actually found?
HR 1.00 primary; HF HR 1.27.
- How large was the observed effect?
HR 1.27 HF
- What do the results mean in everyday life?
Avoid saxagliptin in heart failure risk.
- What are the study's limitations?
Short follow-up; Industry funded
- What does it say about Elawady's specific claim?
- Do the results apply to Germany and Europe?
Multinational/US/UK data; transferable to EU practice.
- What can explicitly not be concluded from this study?
Class-wide harm.
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Canagliflozin heart and kidney trials (CANVAS)
Neal B et al.. N Engl J Med 2017 · PMID 28605608 · DOI 10.1056/NEJMoa1611925Randomised controlled trialcited by the Tayebat archivefull text checked★ key studyFewer heart attacks, strokes and heart deaths (-14%), but more toe/foot amputations.
Does the study support the specific claim? Partly · Methodological quality: high · Certainty of evidence: see overall assessment of the claim
Original publication · Scientific details
Study explained simply
- What did the researchers want to find out?
CV, renal and safety outcomes of canagliflozin
- How was the study done?
Integrated analysis of two double-blind RCTs (CANVAS Program)
- How many people, animals or samples were studied?
10,142; Type 2 diabetes with high CV risk, mean age 63.3
- What was actually found?
14% fewer heart attacks, strokes or heart deaths; about twice as many amputations (6.3 vs 3.4 per 1,000 patient-years), mostly toes; more fractures and genital infections.
- How large was the observed effect?
HR 0.86 / 1.97
- What do the results mean in everyday life?
Both benefits and risks; foot care matters.
- What are the study's limitations?
Funded and co-analysed by the manufacturer; two trials combined; many secondary results only exploratory.
- What does it say about Elawady's specific claim?
- Do the results apply to Germany and Europe?
Multinational/US/UK data; transferable to EU practice.
- What can explicitly not be concluded from this study?
That SGLT2 inhibitors are net harmful.
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Ketoacidosis with canagliflozin
Erondu N et al.. Diabetes Care 2015 · PMID 26203064 · DOI 10.2337/dc15-1251Othercited by the Tayebat archivefull text checkedKetoacidosis was rare (7 per 10,000 patients), often with insulin deficiency or triggers.
Does the study support the specific claim? Partly · Methodological quality: low · Certainty of evidence: see overall assessment of the claim
Original publication · Scientific details
Study explained simply
- What did the researchers want to find out?
Incidence of DKA with canagliflozin
- How was the study done?
Pooled safety analysis of randomised trials
- How many people, animals or samples were studied?
17,596; Type 2 diabetes in canagliflozin program
- What was actually found?
DKA 0.07%.
- How large was the observed effect?
0.52-0.76 vs 0.24 per 1,000 PY
- What do the results mean in everyday life?
Rare but real risk.
- What are the study's limitations?
Analysed and written by manufacturer employees; only 12 cases; based on investigator reports (may miss cases).
- What does it say about Elawady's specific claim?
- Do the results apply to Germany and Europe?
Multinational/US/UK data; transferable to EU practice.
- What can explicitly not be concluded from this study?
Precise relative risk; that euglycaemic DKA is common (cases here had high glucose).
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Ketoacidosis after starting SGLT2 drugs (letter)
Fralick M et al.. N Engl J Med 2017 · PMID 28591538 · DOI 10.1056/NEJMc1701990Cohort studycited by the Tayebat archiveabstract only checkedContent not verified (no abstract).
Does the study support the specific claim? Unclear · Methodological quality: low · Certainty of evidence: see overall assessment of the claim
Original publication · Scientific details
Study explained simply
- What did the researchers want to find out?
Risk of DKA after initiating an SGLT2 inhibitor (per title)
- How was the study done?
Research letter (no abstract in PubMed; full text not accessed)
- How many people, animals or samples were studied?
not verifiable; not verifiable
- What was actually found?
Not verified.
- How large was the observed effect?
not verified
- What do the results mean in everyday life?
See I-ODD-09.
- What are the study's limitations?
Not read; letter format
- What does it say about Elawady's specific claim?
Supports C-ODD-02 (direction).
- Do the results apply to Germany and Europe?
US data.
- What can explicitly not be concluded from this study?
Anything quantitative.
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Fournier gangrene reports with SGLT2 drugs
Bersoff-Matcha SJ et al.. Ann Intern Med 2019 · PMID 31060053 · DOI 10.7326/M19-0085Case series / case reportcited by the Tayebat archiveabstract only checked★ key studyFDA received 55 reports of this rare genital infection with SGLT2 drugs; reports cannot show how often it really happens.
Does the study support the specific claim? Partly · Methodological quality: very low · Certainty of evidence: see overall assessment of the claim
Original publication · Scientific details
Study explained simply
- What did the researchers want to find out?
Describe Fournier gangrene cases with SGLT2 inhibitors vs other agents
- How was the study done?
Descriptive case series of FDA FAERS reports and published cases
- How many people, animals or samples were studied?
55 SGLT2 cases; 19 comparator cases; Adults with diabetes reported to FAERS
- What was actually found?
55 vs 19 reports.
- How large was the observed effect?
not estimable
- What do the results mean in everyday life?
Be alert to genital pain/swelling.
- What are the study's limitations?
No incidence/causality; Reporting bias (stimulated reporting after warnings); Different time windows
- What does it say about Elawady's specific claim?
Supports C-ODD-08 (signal).
- Do the results apply to Germany and Europe?
FDA data; EMA issued similar warnings (not verified).
- What can explicitly not be concluded from this study?
Incidence or causality.
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Canagliflozin and fractures
Watts NB et al.. J Clin Endocrinol Metab 2016 · PMID 26580237 · DOI 10.1210/jc.2015-3167Randomised controlled trialcited by the Tayebat archiveabstract only checkedMore fractures in one trial with older high-risk patients, not in others.
Does the study support the specific claim? Partly · Methodological quality: moderate · Certainty of evidence: see overall assessment of the claim
Original publication · Scientific details
Study explained simply
- What did the researchers want to find out?
Canagliflozin and fracture risk
- How was the study done?
Pooled analysis of 9 phase 3 RCTs incl. CANVAS
- How many people, animals or samples were studied?
10,194; Type 2 diabetes
- What was actually found?
4.0 vs 2.6% in CANVAS.
- How large was the observed effect?
+1.4 pp in CANVAS
- What do the results mean in everyday life?
Fall prevention in frail patients.
- What are the study's limitations?
Pooled post-hoc
- What does it say about Elawady's specific claim?
Supports C-ODD-05 (signal).
- Do the results apply to Germany and Europe?
Multinational/US/UK data; transferable to EU practice.
- What can explicitly not be concluded from this study?
Class effect.
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GLP-1 drugs and pancreatitis in US claims
Singh S et al.. JAMA Intern Med 2013 · PMID 23440284 · DOI 10.1001/jamainternmed.2013.2720Case-control studycited by the Tayebat archiveabstract only checkedUsers had about twice the odds of pancreatitis, but they also had more risk factors.
Does the study support the specific claim? Partly · Methodological quality: low · Certainty of evidence: see overall assessment of the claim
Original publication · Scientific details
Study explained simply
- What did the researchers want to find out?
GLP-1-based therapies and acute pancreatitis
- How was the study done?
Population-based matched case-control (US claims)
- How many people, animals or samples were studied?
1,269 cases, 1,269 controls; Adults 18-64 with type 2 diabetes
- What was actually found?
aOR 2.24.
- How large was the observed effect?
aOR 2.24 (1.36-3.68)
- What do the results mean in everyday life?
Signal not confirmed in trials.
- What are the study's limitations?
Strong confounding; Claims data
- What does it say about Elawady's specific claim?
Supports C-ODD-04.
- Do the results apply to Germany and Europe?
US data.
- What can explicitly not be concluded from this study?
Causation.
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Stomach and bowel side effects of weight-loss injections
Sodhi M et al.. JAMA 2023 · PMID 37796527 · DOI 10.1001/jama.2023.19574Cohort studycited by the Tayebat archiveabstract only checkedNot verified (no abstract).
Does the study support the specific claim? Unclear · Methodological quality: low · Certainty of evidence: see overall assessment of the claim
Original publication · Scientific details
Study explained simply
- What did the researchers want to find out?
GI adverse events with GLP-1 RAs used for weight loss (per title)
- How was the study done?
Research letter; retrospective cohort (no abstract in PubMed; full text could not be retrieved)
- How many people, animals or samples were studied?
not verifiable; not verifiable
- What was actually found?
Not verified.
- How large was the observed effect?
not verified
- What do the results mean in everyday life?
GI side effects are common with GLP-1 RAs (RCTs).
- What are the study's limitations?
Not read
- What does it say about Elawady's specific claim?
Background for C-ODD-04.
- Do the results apply to Germany and Europe?
unknown
- What can explicitly not be concluded from this study?
Anything quantitative.
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Semaglutide and optic nerve stroke
Hathaway JT et al.. JAMA Ophthalmol 2024 · PMID 38958939 · DOI 10.1001/jamaophthalmol.2024.2296Cohort studycited by the Tayebat archiveabstract only checked★ key studyIn an eye-clinic registry, semaglutide users had about 4 times more NAION, but numbers were small.
Does the study support the specific claim? Partly · Methodological quality: low · Certainty of evidence: see overall assessment of the claim
Original publication · Scientific details
Study explained simply
- What did the researchers want to find out?
Semaglutide and NAION risk
- How was the study done?
Retrospective matched cohort from a neuro-ophthalmology registry
- How many people, animals or samples were studied?
16,827 screened; 710 T2D, 979 overweight/obese; Patients evaluated by neuro-ophthalmologists at one academic institution
- What was actually found?
HR 4.28 (T2D).
- How large was the observed effect?
HR 4.28 (1.62-11.29)
- What do the results mean in everyday life?
Possible rare eye risk.
- What are the study's limitations?
Referral population (selection bias); Few events; Single centre
- What does it say about Elawady's specific claim?
Supports C-ODD-10.
- Do the results apply to Germany and Europe?
US data.
- What can explicitly not be concluded from this study?
Causation or population incidence.
No study in this group is marked as key.
Studies contradicting or limiting the claim (7)
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Metformin in overweight type 2 diabetes (UKPDS 34)
UKPDS Group. Lancet 1998 · PMID 9742977Randomised controlled trialindependent cross-checkabstract only checked★ key studyMetformin reduced deaths from any cause by about a third over 10 years.
Does the study support the specific claim? No · Methodological quality: moderate · Certainty of evidence: see overall assessment of the claim
Original publication · Scientific details
Study explained simply
- What did the researchers want to find out?
Intensive control with metformin in overweight type 2 diabetes
- How was the study done?
RCT within UKPDS (UKPDS 34)
- How many people, animals or samples were studied?
753 (main comparison); Overweight newly diagnosed type 2 diabetes, mean age 53
- What was actually found?
Mortality -36%.
- How large was the observed effect?
RR reduction 36% (9-55)
- What do the results mean in everyday life?
Metformin is protective.
- What are the study's limitations?
Small arms; Open-label; Conflicting supplementary result
- What does it say about Elawady's specific claim?
- Do the results apply to Germany and Europe?
UK.
- What can explicitly not be concluded from this study?
Effects in non-overweight patients.
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Empagliflozin heart trial
Zinman B et al.. N Engl J Med 2015 · PMID 26378978 · DOI 10.1056/NEJMoa1504720Randomised controlled trialindependent cross-checkabstract only checked★ key studyDeaths fell from 8.3% to 5.7% over about 3 years.
Does the study support the specific claim? No · Methodological quality: high · Certainty of evidence: see overall assessment of the claim
Original publication · Scientific details
Study explained simply
- What did the researchers want to find out?
CV outcomes of empagliflozin in type 2 diabetes at high CV risk
- How was the study done?
Double-blind placebo-controlled RCT (EMPA-REG OUTCOME)
- How many people, animals or samples were studied?
7,020; Type 2 diabetes with high CV risk
- What was actually found?
Primary 10.
- How large was the observed effect?
HR 0.86; death -32%
- What do the results mean in everyday life?
This drug class protects heart and/or kidneys in the studied patients.
- What are the study's limitations?
Industry funded; Selected high-risk population
- What does it say about Elawady's specific claim?
- Do the results apply to Germany and Europe?
Multinational trial including European sites or directly applicable to EU practice.
- What can explicitly not be concluded from this study?
Benefit in low-risk people; absence of side effects.
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Dapagliflozin (Forxiga) in kidney disease
Heerspink HJL et al.. N Engl J Med 2020 · PMID 32970396 · DOI 10.1056/NEJMoa2024816Randomised controlled trialindependent cross-checkfull text checked★ key studyForxiga reduced kidney failure and deaths; the trial was stopped early because the benefit was clear.
Does the study support the specific claim? No · Methodological quality: high · Certainty of evidence: see overall assessment of the claim
Original publication · Scientific details
Study explained simply
- What did the researchers want to find out?
Dapagliflozin in CKD with/without diabetes
- How was the study done?
Double-blind placebo-controlled RCT (DAPA-CKD)
- How many people, animals or samples were studied?
4,304; CKD (eGFR 25-75, albuminuria)
- What was actually found?
Kidney failure, kidney decline or kidney/heart death: 9.2% with dapagliflozin vs 14.5% with placebo; deaths 4.7% vs 6.8%. Amputations 1.6% vs 1.8%; no ketoacidosis cases with dapagliflozin (2 with placebo).
- How large was the observed effect?
HR 0.61; death HR 0.69
- What do the results mean in everyday life?
This drug class protects heart and/or kidneys in the studied patients.
- What are the study's limitations?
Industry funded; stopped early for benefit (can overstate effect); selected high-risk CKD population; type 1 diabetes excluded; median 2.4 years follow-up.
- What does it say about Elawady's specific claim?
Contradicts C-ODD-06 (Forxiga 'kills'); context for C-ODD-02.
- Do the results apply to Germany and Europe?
Multinational trial including European sites or directly applicable to EU practice.
- What can explicitly not be concluded from this study?
Benefit in low-risk people; absence of side effects.
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Dapagliflozin in heart failure
McMurray JJV et al.. N Engl J Med 2019 · PMID 31535829 · DOI 10.1056/NEJMoa1911303Randomised controlled trialindependent cross-checkabstract only checked★ key studyFewer heart failure worsenings and deaths with Forxiga.
Does the study support the specific claim? No · Methodological quality: high · Certainty of evidence: see overall assessment of the claim
Original publication · Scientific details
Study explained simply
- What did the researchers want to find out?
Dapagliflozin in heart failure with reduced EF
- How was the study done?
Double-blind placebo-controlled RCT (DAPA-HF)
- How many people, animals or samples were studied?
4,744; HFrEF NYHA II-IV, EF <=40%, with/without diabetes
- What was actually found?
Primary 16.
- How large was the observed effect?
HR 0.74; death HR 0.83
- What do the results mean in everyday life?
This drug class protects heart and/or kidneys in the studied patients.
- What are the study's limitations?
Industry funded; Selected high-risk population
- What does it say about Elawady's specific claim?
Contradicts C-ODD-06.
- Do the results apply to Germany and Europe?
Multinational trial including European sites or directly applicable to EU practice.
- What can explicitly not be concluded from this study?
Benefit in low-risk people; absence of side effects.
-
Semaglutide heart safety trial
Marso SP et al.. N Engl J Med 2016 · PMID 27633186 · DOI 10.1056/NEJMoa1607141Randomised controlled trialindependent cross-checkabstract only checked★ key studyFewer heart attacks/strokes, but more diabetic eye complications and stomach side effects.
Does the study support the specific claim? No · Methodological quality: high · Certainty of evidence: see overall assessment of the claim
Original publication · Scientific details
Study explained simply
- What did the researchers want to find out?
CV safety of semaglutide
- How was the study done?
Double-blind placebo-controlled RCT (SUSTAIN-6)
- How many people, animals or samples were studied?
3,297; Type 2 diabetes, 83% with CVD/CKD
- What was actually found?
Primary 6.
- How large was the observed effect?
HR 0.74
- What do the results mean in everyday life?
This drug class protects heart and/or kidneys in the studied patients.
- What are the study's limitations?
Industry funded; Selected high-risk population
- What does it say about Elawady's specific claim?
Contradicts C-ODD-06; GI and retinopathy harms relevant to C-ODD-05.
- Do the results apply to Germany and Europe?
Multinational trial including European sites or directly applicable to EU practice.
- What can explicitly not be concluded from this study?
Benefit in low-risk people; absence of side effects.
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Fournier gangrene in SGLT2 trials
Silverii GA et al.. Diabetes Obes Metab 2020 · PMID 31637829 · DOI 10.1111/dom.13900Meta-analysisindependent cross-checkabstract only checkedAcross 84 trials Fournier gangrene was not more frequent, but cases were too few to be sure.
Does the study support the specific claim? No · Methodological quality: moderate · Certainty of evidence: see overall assessment of the claim
Original publication · Scientific details
Study explained simply
- What did the researchers want to find out?
SGLT2 inhibitors and Fournier gangrene
- How was the study done?
Meta-analysis of 84 RCTs
- How many people, animals or samples were studied?
42,415 SGLT2i vs 27,158 comparators; Type 2 diabetes in RCTs
- What was actually found?
OR 0.41 (n.s.).
- How large was the observed effect?
MH-OR 0.41 (0.09-1.82)
- What do the results mean in everyday life?
Very rare; no confirmed excess.
- What are the study's limitations?
Very few events; FG not systematically adjudicated
- What does it say about Elawady's specific claim?
Limits C-ODD-08.
- Do the results apply to Germany and Europe?
Multinational trial including European sites or directly applicable to EU practice.
- What can explicitly not be concluded from this study?
Exclude risk.
-
RECORD: rosiglitazone heart outcomes
Home PD et al.. Lancet 2009 · PMID 19501900 · DOI 10.1016/S0140-6736(09)60953-3Randomised controlled trialindependent cross-checkabstract only checked★ key studyOverall heart outcomes were not worse, but heart failure doubled; heart-attack effect unclear.
Does the study support the specific claim? Partly · Methodological quality: moderate · Certainty of evidence: see overall assessment of the claim
Original publication · Scientific details
Study explained simply
- What did the researchers want to find out?
CV outcomes of add-on rosiglitazone
- How was the study done?
Multicentre open-label RCT (RECORD main results)
- How many people, animals or samples were studied?
4,447; Type 2 diabetes on metformin or SU, HbA1c 7.9%
- What was actually found?
Non-inferior CV; HF HR 2.10.
- How large was the observed effect?
HR 0.99 primary
- What do the results mean in everyday life?
Avoid in heart failure.
- What are the study's limitations?
Open-label; Manufacturer funded; Low event rates
- What does it say about Elawady's specific claim?
Supports HF part, limits MI part of C-ODD-09; limits C-ODD-05.
- Do the results apply to Germany and Europe?
European trial.
- What can explicitly not be concluded from this study?
Settle MI risk.
No study in this group is marked as key.
Studies with mixed or unclear results (2)
-
Canagliflozin in diabetic kidney disease
Perkovic V et al.. N Engl J Med 2019 · PMID 30990260 · DOI 10.1056/NEJMoa1811744Randomised controlled trialindependent cross-checkfull text checked★ key studyKidney failure and heart problems fell by about a third; amputations and fractures were not increased, but rare ketoacidosis was more common (11 vs 1 cases).
Does the study support the specific claim? No · Methodological quality: high · Certainty of evidence: see overall assessment of the claim
Original publication · Scientific details
Study explained simply
- What did the researchers want to find out?
Canagliflozin and renal outcomes in type 2 diabetes with nephropathy
- How was the study done?
Double-blind placebo-controlled RCT (CREDENCE)
- How many people, animals or samples were studied?
4,401; Type 2 diabetes with albuminuric CKD
- What was actually found?
Primary kidney/heart outcome 43.2 vs 61.2 per 1000 patient-years (30% lower); amputation 12.3 vs 11.2 per 1000 patient-years (not significant); diabetic ketoacidosis 2.2 vs 0.2 per 1000 patient-years.
- How large was the observed effect?
HR 0.70
- What do the results mean in everyday life?
This drug class protects heart and/or kidneys in the studied patients.
- What are the study's limitations?
Industry funded; stopped early for benefit; selected high-risk population; foot checks added during the trial may have lowered amputation risk; rare harms imprecise.
- What does it say about Elawady's specific claim?
Contradicts C-ODD-06; limits amputation/fracture signals in C-ODD-05.
- Do the results apply to Germany and Europe?
Multinational trial including European sites or directly applicable to EU practice.
- What can explicitly not be concluded from this study?
Benefit in low-risk people; absence of side effects (ketoacidosis was increased); amputation safety in routine care without foot surveillance.
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Liraglutide heart trial
Marso SP et al.. N Engl J Med 2016 · PMID 27295427 · DOI 10.1056/NEJMoa1603827Randomised controlled trialindependent cross-checkfull text checked★ key studyFewer heart deaths and deaths overall; pancreatitis not increased, but more gallstone disease and a small, non-significant excess of pancreatic cancer.
Does the study support the specific claim? No · Methodological quality: high · Certainty of evidence: see overall assessment of the claim
Original publication · Scientific details
Study explained simply
- What did the researchers want to find out?
CV outcomes of liraglutide
- How was the study done?
Double-blind placebo-controlled RCT (LEADER)
- How many people, animals or samples were studied?
9,340; Type 2 diabetes with high CV risk
- What was actually found?
Heart attack, stroke or heart death 13.0% vs 14.9%; deaths 8.2% vs 9.6%; acute pancreatitis 18 vs 23 patients; pancreatic cancer 13 vs 5 (not significant); gallstone disease 3.1% vs 1.9%.
- How large was the observed effect?
HR 0.87; death HR 0.85
- What do the results mean in everyday life?
This drug class protects heart and/or kidneys in the studied patients.
- What are the study's limitations?
Industry funded with sponsor co-analysis; high-risk population; safety outcomes not powered and not adjusted for multiple testing; 3.5-5 years follow-up.
- What does it say about Elawady's specific claim?
- Do the results apply to Germany and Europe?
Multinational trial including European sites or directly applicable to EU practice.
- What can explicitly not be concluded from this study?
Benefit in low-risk people; that pancreatic cancer risk is absent or present (too few cases); anything about pancreatic cysts.
No study in this group is marked as key.
Regional context
Germany / EU
European (EASD) and German (DDG) guidance follow the same evidence base as the ADA/EASD consensus: individualised HbA1c targets, insulin as mandatory therapy in type 1 diabetes, and SGLT2 inhibitors/GLP-1 receptor agonists for people with cardiovascular or kidney disease. No country-specific difference changes the assessment.
Egypt
Egypt has one of the highest diabetes prevalences in the region; the same drug classes and insulins are used. Access barriers and cost may make advice to stop medication attractive, which increases the practical risk of this claim. No Egypt-specific evidence changes the assessment.
What applies in my country?
General scientific assessment
Mostly true Each listed harm signal exists, but the list is one-sided and omits proven benefits.
This statement concerns biological or medical relationships. The scientific assessment above applies regardless of the country; country-specific food data do not change it.
References
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- Heart failure events with rosiglitazone in type 2 diabetes: data from the RECORD clinical trial.. Komajda M et al.. Eur Heart J 2010 · PMID 20118174 · DOI 10.1093/eurheartj/ehp604
- Pioglitazone use and risk of bladder cancer: population based cohort study.. Tuccori M et al.. BMJ 2016 · PMID 27029385 · DOI 10.1136/bmj.i1541
- Long term treatment with metformin in patients with type 2 diabetes and risk of vitamin B-12 deficiency: randomised placebo controlled trial.. de Jager J et al.. BMJ 2010 · PMID 20488910 · DOI 10.1136/bmj.c2181
- Association of biochemical B₁₂ deficiency with metformin therapy and vitamin B₁₂ supplements: the National Health and Nutrition Examination Survey, 1999-2006.. Reinstatler L et al.. Diabetes Care 2012 · PMID 22179958 · DOI 10.2337/dc11-1582
- Long-term Metformin Use and Vitamin B12 Deficiency in the Diabetes Prevention Program Outcomes Study.. Aroda VR et al.. J Clin Endocrinol Metab 2016 · PMID 26900641 · DOI 10.1210/jc.2015-3754
- Comparative effectiveness of sulfonylurea and metformin monotherapy on cardiovascular events in type 2 diabetes mellitus: a cohort study.. Roumie CL et al.. Ann Intern Med 2012 · PMID 23128859 · DOI 10.7326/0003-4819-157-9-201211060-00003
- Saxagliptin and cardiovascular outcomes in patients with type 2 diabetes mellitus.. Scirica BM et al.. N Engl J Med 2013 · PMID 23992601 · DOI 10.1056/NEJMoa1307684
- Canagliflozin and Cardiovascular and Renal Events in Type 2 Diabetes.. Neal B et al.. N Engl J Med 2017 · PMID 28605608 · DOI 10.1056/NEJMoa1611925
- Diabetic Ketoacidosis and Related Events in the Canagliflozin Type 2 Diabetes Clinical Program.. Erondu N et al.. Diabetes Care 2015 · PMID 26203064 · DOI 10.2337/dc15-1251
- Risk of Diabetic Ketoacidosis after Initiation of an SGLT2 Inhibitor.. Fralick M et al.. N Engl J Med 2017 · PMID 28591538 · DOI 10.1056/NEJMc1701990
- Fournier Gangrene Associated With Sodium-Glucose Cotransporter-2 Inhibitors: A Review of Spontaneous Postmarketing Cases.. Bersoff-Matcha SJ et al.. Ann Intern Med 2019 · PMID 31060053 · DOI 10.7326/M19-0085
- Effects of Canagliflozin on Fracture Risk in Patients With Type 2 Diabetes Mellitus.. Watts NB et al.. J Clin Endocrinol Metab 2016 · PMID 26580237 · DOI 10.1210/jc.2015-3167
- Glucagonlike peptide 1-based therapies and risk of hospitalization for acute pancreatitis in type 2 diabetes mellitus: a population-based matched case-control study.. Singh S et al.. JAMA Intern Med 2013 · PMID 23440284 · DOI 10.1001/jamainternmed.2013.2720
- Risk of Gastrointestinal Adverse Events Associated With Glucagon-Like Peptide-1 Receptor Agonists for Weight Loss.. Sodhi M et al.. JAMA 2023 · PMID 37796527 · DOI 10.1001/jama.2023.19574
- Risk of Nonarteritic Anterior Ischemic Optic Neuropathy in Patients Prescribed Semaglutide.. Hathaway JT et al.. JAMA Ophthalmol 2024 · PMID 38958939 · DOI 10.1001/jamaophthalmol.2024.2296
- Effect of intensive blood-glucose control with metformin on complications in overweight patients with type 2 diabetes (UKPDS 34). UK Prospective Diabetes Study (UKPDS) Group.. UKPDS Group. Lancet 1998 · PMID 9742977
- Empagliflozin, Cardiovascular Outcomes, and Mortality in Type 2 Diabetes.. Zinman B et al.. N Engl J Med 2015 · PMID 26378978 · DOI 10.1056/NEJMoa1504720
- Dapagliflozin in Patients with Chronic Kidney Disease.. Heerspink HJL et al.. N Engl J Med 2020 · PMID 32970396 · DOI 10.1056/NEJMoa2024816
- Dapagliflozin in Patients with Heart Failure and Reduced Ejection Fraction.. McMurray JJV et al.. N Engl J Med 2019 · PMID 31535829 · DOI 10.1056/NEJMoa1911303
- Semaglutide and Cardiovascular Outcomes in Patients with Type 2 Diabetes.. Marso SP et al.. N Engl J Med 2016 · PMID 27633186 · DOI 10.1056/NEJMoa1607141
- Fournier's gangrene and sodium-glucose co-transporter-2 inhibitors: A meta-analysis of randomized controlled trials.. Silverii GA et al.. Diabetes Obes Metab 2020 · PMID 31637829 · DOI 10.1111/dom.13900
- Rosiglitazone evaluated for cardiovascular outcomes in oral agent combination therapy for type 2 diabetes (RECORD): a multicentre, randomised, open-label trial.. Home PD et al.. Lancet 2009 · PMID 19501900 · DOI 10.1016/S0140-6736(09)60953-3
- Canagliflozin and Renal Outcomes in Type 2 Diabetes and Nephropathy.. Perkovic V et al.. N Engl J Med 2019 · PMID 30990260 · DOI 10.1056/NEJMoa1811744
- Liraglutide and Cardiovascular Outcomes in Type 2 Diabetes.. Marso SP et al.. N Engl J Med 2016 · PMID 27295427 · DOI 10.1056/NEJMoa1603827