Glucagon-like peptide 1 receptor agonist use and risk of thyroid cancer: Scandinavian cohort study
- Design
- Retrospective cohort · 437077 participants · Hard outcome
- Match to healthy normal-weight adults aged 55–75
- Different populationDiabetes populations; follow-up short for thyroid cancer latency.
- Could weight loss explain it?
- Unknown[Auto] Not addressed in abstract.
- Study tier
- Study tier 3Large multinational register cohort with cancer-register outcomes; short follow-up.
- Assessment
- Version 2 · curated · Sep 13, 2026
Study facts come from the paper. Population match, weight-loss explanation and study tier are our judgments, made against the reference group of healthy normal-weight adults aged 55–75.
In 145,410 Scandinavian GLP-1 users followed for about 4 years, thyroid cancer was not increased compared with DPP-4 inhibitor users (HR 0.93). Follow-up is too short to rule out very long-latency effects.
01Findings
What the study reported
- Drugs
- Class unspecified
- Comparator
- DPP-4 inhibitors (main) and SGLT2 inhibitors
- Primary outcome
- Thyroid cancer (national cancer registers)
- Effect
- HR 0.93; medullary HR 1.19; vs SGLT2i HR 1.16
- 95% confidence interval
- 0.66 to 1.31
- Follow-up
- mean 3.9 years
- Adverse events
- Not extracted
- Limitations
- Auto-classified from abstract only; effect estimates, adverse events and limitations not extracted. Requires manual review.
Who was studied
- Diabetes status
- type 2 diabetes (glucose-lowering users)
- Sample size
- 410
Study quality details
- Study design
- Retrospective cohort
- Sample size
- 410
- Randomization
- no
- Blinding
- not stated
- Comparator
- active comparator
- Follow up duration
- 3.9 years
- Outcome type
- unknown
- Replication
- not assessed (auto)
- Consistency with other evidence
- not assessed (auto)
- Population applicability
- UNKNOWN
- Statistical precision
- upper CI 1.31 excludes large increases
- Risk of bias
- active-comparator design; observational
- Funding conflicts
- unclear
- Peer review status
- yes
02Funding
Funding and conflicts
- Funding
- Swedish Cancer Society, Swedish Research Council, Karolinska Institutet, Novo Nordisk Foundation, other foundations
- Industry funded
- Partial
- Manufacturer
- Novo Nordisk Foundation (independent foundation; majority shareholder of the company)
- Sponsor role
- Foundation grant; no company role stated.
- Author conflicts
- One author employed by NordicRWE; another reports fees from Novo Nordisk, Eli Lilly and others.
- Independent replication
- contradicted by French case-control (PMID 36356111)
Funding is shown on every study and never used to score it.
03Claims
Claims this study bears on
- GLP-1 receptor agonists increase the risk of thyroid cancer in humans.Contradicts
Scandinavian cohort, 145,410 users: HR 0.93 (0.66-1.31) vs DPP-4 inhibitors.
04Source
The source, as retrieved
Abstract
[OBJECTIVE] To investigate whether use of glucagon-like peptide 1 (GLP1) receptor agonists is associated with increased risk of thyroid cancer. [DESIGN] Scandinavian cohort study. [SETTING] Denmark, Norway, and Sweden, 2007-21. [PARTICIPANTS] Patients who started GLP1 receptor agonist treatment were compared with patients who started dipeptidyl peptidase 4 (DPP4) inhibitor treatment, and in an additional analysis, patients who started sodium-glucose cotransporter 2 (SGLT2) inhibitor treatment. [MAIN OUTCOME MEASURES] Thyroid cancer identified from nationwide cancer registers. An active-comparator new user study design was used to minimise risks of confounding and time related biases from using real world studies of drug effects. Cox regression was used to estimate hazard ratios, controlling for potential confounders with propensity score weighting. [RESULTS] The mean follow-up time was 3.9 years (standard deviation 3.5 years) in the GLP1 receptor agonist group and 5.4 years (standard deviation 3.5 years) in the DPP4 inhibitor group. 76 of 145 410 patients (incidence rate 1.33 events per 10 000 person years) treated with GLP1 receptor agonists and 184 of 291 667 patients (incidence rate 1.46 events per 10 000 person years) treated with DPP4 inhibitors developed thyroid cancer. GLP1 receptor agonist use was not associated with increased risk of thyroid cancer (hazard ratio 0.93, 95% confidence interval 0.66 to 1.31; rate difference -0.13, 95% confidence interval -0.61 to 0.36 events per 10 000 person years). The hazard ratio for medullary thyroid cancer was 1.19 (0.37 to 3.86). In the additional analysis comparing the GLP1 receptor agonist group with the SGLT2 inhibitor group, the hazard ratio for thyroid cancer was 1.16 (0.65 to 2.05). [CONCLUSIONS] In this large cohort study using nationwide data from three countries, GLP1 receptor agonist use was not associated with a substantially increased risk of thyroid cancer over a mean follow-up of 3.9 years. In the main analysis comparing GLP1 receptor agonists with DPP4 inhibitors, the upper limit of the confidence interval was consistent with no more than a 31% increase in relative risk.
Where this record came from
| Source | Retrieved | Identifier |
|---|---|---|
| pubmed | Sep 13, 2026 | 38683947 first ingestion |