Narrative reviewindependent cross-checkabstract only checked I-INTC-06 standard review
How meals trigger insulin
Incretin hormones: Their role in health and disease.
Overview
Nauck MA et al.. Diabetes Obes Metab 2018 · PMID 29364588 · DOI 10.1111/dom.13129
After eating, gut hormones and rising blood sugar make the pancreas release insulin; oral glucose triggers 2-3 times more insulin than glucose given into a vein.
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?
Review incretin physiology
- How was the study done?
Narrative review
- How many people, animals or samples were studied?
not applicable
- What was actually found?
Gut hormones amplify insulin release after meals
- How large was the observed effect?
2-3-fold incretin effect
- What do the results mean in everyday life?
Insulin rises after meals through normal gut signals.
- What are the study's limitations?
Narrative review
- What does it say about Elawady's specific claim?
Contradicts obstruction as the cause of high insulin
- Do the results apply to Germany and Europe?
High
- What can explicitly not be concluded from this study?
Not applicable
Scientific in-depth review
1. Full reference
- Authors
- Nauck MA et al.
- Journal
- Diabetes Obes Metab
- Year
- 2018
- Identifier
- PMID 29364588 DOI 10.1111/dom.13129
- Verification
- verified – PubMed efetch 2026-10-25
- Retracted
- no
- Corrections
- none
- Extent checked
- abstract only
- Conflicts of interest and funding
not stated in abstract (PubMed lists non-US government support)
2. Research question
What role do incretin hormones play in health and disease?
3. Study design and population
- Study design
- Narrative review – Narrative review of incretin physiology (GIP, GLP-1)
- Population
Humans (physiology and clinical studies)
- Country
International
- Period
not applicable
- Sample size
not applicable
- Inclusion and exclusion criteria
not applicable
4. Methods and endpoints
- Exposure / intervention
Oral nutrient intake
- Comparator
Intravenous glucose
- Endpoints
Insulin secretion
- Statistical methods
not applicable
5. Actual results
- Results
Abstract: incretin hormones (GIP from K cells, GLP-1 from L cells) are secreted after nutrient intake and stimulate insulin secretion together with hyperglycaemia; they are responsible for a two- to three-fold higher insulin response to oral than to intravenous glucose; in type 2 diabetes the incretin effect is diminished.
- Absolute risks
not applicable
- Authors' conclusion
Incretins are physiologically important and involved in the pathophysiology of obesity and type 2 diabetes.
6. Strengths
- Leading authors in the field
7. Weaknesses
- Narrative review
- Abstract only
8. Risk of bias
- Orienting tool
- none applicable
- Type of assessment
- simplified assessment (abstract only)
- Full formal assessment
- no
- Overall risk of bias
- not assessable
- Rationale
Narrative review.
9. Assessment of the statistical interpretation
The 2-3-fold figure describes the incretin effect in healthy people.
10. Relevance to the specific claim
Explains the established mechanism of post-meal insulin release (absorbed nutrients plus gut hormones), which does not require any obstruction.
11. Independent contrary findings
None.
12. Transferability to Germany and Europe
Universal physiology.
13. Overall methodological judgement
Background source on post-meal insulin physiology.
| Multidimensional assessment | |
|---|---|
| Authenticity of the source | verified |
| Methodological quality | moderate |
| Risk of bias | not assessable |
| Precision of results | not applicable |
| Directness | indirect |
| Reproducibility | replicated |
| Consistency with the overall evidence | consistent |
| Regional transferability | high |
| Adequacy of the interpretation (by the archive) | not applicable |
14. Open questions
None for this claim.