Cross-sectional studyindependent cross-checkabstract checked★ key study I-INS-106 in-depth review
Height of children with type 1 diabetes and their insulin treatment
The influence of treatment, age at onset, and metabolic control on height in children and adolescents with type 1 diabetes-A SWEET collaborative study.
Overview
Svensson J et al.. Pediatr Diabetes 2018 · PMID 30105887 · DOI 10.1111/pedi.12751
In about 23,000 young people, those on more intensive insulin treatment were taller; major growth problems were virtually absent with modern care.
Does the study support the specific claim? No · Methodological quality: moderate
Plain-language summary
Study explained simply
- What did the researchers want to find out?
Describe height by treatment and control in youth with T1D.
- How was the study done?
International registry, cross-sectional.
- How many people, animals or samples were studied?
22,941 young people.
- What was actually found?
Height normal or above; pumps and good control linked to taller height.
- How large was the observed effect?
z-score 0.35 vs 0.19.
- What do the results mean in everyday life?
Modern insulin treatment lets children grow normally.
- What are the study's limitations?
Cross-sectional; industry funding.
- What does it say about Elawady's specific claim?
Contradicts 'insulin before puberty is a catastrophe'.
- Do the results apply to Germany and Europe?
Includes European centres.
- What can explicitly not be concluded from this study?
Cannot prove causality.
Scientific in-depth review
1. Full reference
- Authors
- Svensson J et al.
- Journal
- Pediatr Diabetes
- Year
- 2018
- Identifier
- PMID 30105887 DOI 10.1111/pedi.12751
- Verification
- verified – PubMed efetch 2026-10-26; Crossref 2026-10-26
- Retracted
- no
- Corrections
- none
- Extent checked
- abstract only
- Conflicts of interest and funding
Johnson & Johnson grant listed (record).
2. Research question
How are height, treatment modality and HbA1c associated in youth with T1D?
3. Study design and population
- Study design
- Cross-sectional study – International multicentre cross-sectional registry analysis (SWEET, 55 centres)
- Population
Youth <20 years with T1D >1 year, without coeliac disease
- Country
International (55 centres)
- Period
Registry data (as in paper)
- Sample size
22,941
- Inclusion and exclusion criteria
Age <20, duration >1 year, no coeliac disease
4. Methods and endpoints
- Exposure / intervention
Insulin regimen (pump, >3 injections/day, 0-3 injections/day), HbA1c
- Comparator
Between treatment and HbA1c categories
- Endpoints
Height z-score (WHO charts)
- Statistical methods
Hierarchical regression adjusted for confounders
5. Actual results
- Results
Median height z-score +0.34 (above average). Adjusted height z-score higher with pump use (0.35) than >3 injections/day (0.25) and 0-3 injections/day (0.19). High HbA1c and low-to-normal weight associated with lower height z-score.
- Absolute risks
not reported
- Authors' conclusion
For youths treated at centres offering modern diabetes management, major growth disturbances are virtually eliminated.
6. Strengths
- Very large international sample
- Adjusted models
7. Weaknesses
- Cross-sectional
- Industry grant
- Centre selection
8. Risk of bias
- Orienting tool
- ROBINS-E
- Type of assessment
- simplified assessment (abstract only)
- Full formal assessment
- no
- Overall risk of bias
- some concerns
- Rationale
Cross-sectional; confounding by centre and social factors.
9. Assessment of the statistical interpretation
Differences in z-score are small; direction is the opposite of the claim (more intensive insulin, better growth).
10. Relevance to the specific claim
Children on modern intensive insulin treatment grow normally (above-average height); worse control and fewer injections go with lower height.
11. Independent contrary findings
12. Transferability to Germany and Europe
Directly applicable; same biology and clinical standards in Europe.
13. Overall methodological judgement
Supports that insulin does not stunt growth; under-treatment does.
| Multidimensional assessment | |
|---|---|
| Authenticity of the source | verified |
| Methodological quality | moderate |
| Risk of bias | some concerns |
| Precision of results | high |
| Directness | direct |
| Reproducibility | partly replicated |
| Consistency with the overall evidence | consistent |
| Regional transferability | high |
| Adequacy of the interpretation (by the archive) | not applicable |