Narrative reviewindependent cross-checkabstract only checked I-INTB-01 standard review
Review: how insulin works and how insulin resistance arises
Mechanisms of Insulin Action and Insulin Resistance.
Overview
Petersen MC, Shulman GI. Physiol Rev 2018 · PMID 30067154 · DOI 10.1152/physrev.00063.2017
Insulin resistance in muscle, liver and fat is a central process in type 2 diabetes; some mechanisms are still debated.
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?
Summarise insulin action and resistance
- How was the study done?
Narrative review
- How many people, animals or samples were studied?
Literature
- What was actually found?
Insulin resistance is a key process in type 2 diabetes
- How large was the observed effect?
not applicable
- What do the results mean in everyday life?
Doctors and scientists treat insulin resistance as a real, measurable state.
- What are the study's limitations?
Narrative; abstract only
- What does it say about Elawady's specific claim?
Contradicts 'there is no such thing as insulin resistance'.
- Do the results apply to Germany and Europe?
Universal physiology
- What can explicitly not be concluded from this study?
Does not settle which mediator causes insulin resistance.
Scientific in-depth review
1. Full reference
- Authors
- Petersen MC, Shulman GI
- Journal
- Physiol Rev
- Year
- 2018
- Identifier
- PMID 30067154 DOI 10.1152/physrev.00063.2017
- Verification
- verified – PubMed efetch 2026-10-25
- Retracted
- no
- Corrections
- none
- Extent checked
- abstract only
- Conflicts of interest and funding
Research Support, N.I.H. (publication type in PubMed record); no COI statement in record
2. Research question
What are the mechanisms of normal insulin action and of insulin resistance?
3. Study design and population
- Study design
- Narrative review – Comprehensive narrative review of insulin action and insulin resistance in muscle, liver and white adipose tissue
- Population
Human and animal physiology literature
- Country
not applicable
- Period
literature up to 2018
- Sample size
not applicable
- Inclusion and exclusion criteria
not stated
4. Methods and endpoints
- Exposure / intervention
not applicable
- Comparator
not applicable
- Endpoints
Mechanisms of insulin action and resistance
- Statistical methods
none (narrative)
5. Actual results
- Results
Describes insulin resistance as one of the key pathophysiological processes in type 2 diabetes; reviews evidence for and against putative mediators (diacylglycerol, ceramide, acylcarnitine, ER and mitochondrial stress, inflammatory mediators, branched-chain amino acids, adipokines, hepatokines) and proposes an integrated model linking them to metabolite-driven gluconeogenesis and ectopic lipid accumulation.
- Absolute risks
not applicable
- Authors' conclusion
Insulin resistance is a key pathophysiological process in type 2 diabetes; several mediators remain controversial.
6. Strengths
- Authoritative, comprehensive review by leading investigators of insulin action
7. Weaknesses
- Narrative, not systematic
- Abstract only read
- Mechanistic; does not by itself quantify clinical outcomes
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; no formal risk-of-bias tool applies.
9. Assessment of the statistical interpretation
Not a quantitative synthesis; used only to document that insulin resistance is an established, measurable and intensively studied phenomenon.
10. Relevance to the specific claim
Contradicts the claim that insulin resistance does not exist.
11. Independent contrary findings
The review itself notes that some mechanisms remain controversial.
12. Transferability to Germany and Europe
Physiology is universal.
13. Overall methodological judgement
Establishes insulin resistance as a recognised physiological concept; mechanisms are partly debated.
| Multidimensional assessment | |
|---|---|
| Authenticity of the source | verified |
| Methodological quality | moderate |
| Risk of bias | not assessable |
| Precision of results | not applicable |
| Directness | direct |
| Reproducibility | replicated |
| Consistency with the overall evidence | consistent |
| Regional transferability | high |
| Adequacy of the interpretation (by the archive) | not applicable |
14. Open questions
Which mediators are causal in humans.
15. Linked fact checks
- 'Insulin resistance' is a wrong term; there is no such thing as insulin resistance. – Studies contradicting or limiting the claim