B
Hud 1992: Acanthosis Nigricans as Hyperinsulinemia Marker
Hud et al. • Archives of Dermatology • 1992
Acanthosis nigricans present in 74% of obese patients and marks hyperinsulinemia
Insulin Resistancephysical signsacanthosis nigricans+1 more
Scientific References
The research behind Metabolicum's evidence-based approach
How We Evaluate Evidence
Not all research is equal. We assign confidence grades to each source based on study design, sample size, replication status, and methodology. This helps you understand how confident you can be in each finding.
Grade A
High Confidence
Replicated findings across multiple well-designed studies
Grade B
Good Confidence
Well-designed single studies with strong methodology
Grade C
Moderate Confidence
Observational data with consistent patterns
Grade D
Emerging Evidence
Mechanistic or theoretical - interpret cautiously
Grade E
Clinical Consensus
Practitioner experience without formal trials
Understanding the Reproducibility Crisis
Why are we so careful about evidence grading? Because a significant portion of published research fails to replicate.
| Study | Finding | Grade |
|---|---|---|
| Begley & Ellis, 2012 | Only 21% of landmark cancer studies could be replicated | A |
| Open Science Collaboration, 2015 | Only 36% of psychology studies replicated | A |
| Ioannidis, 2005 | Theoretical framework explaining why most findings are false | A |
This doesn't mean you should distrust all research. It means:
- •Single studies warrant caution — Replication matters
- •Peer review is necessary but not sufficient — Many peer-reviewed findings are later overturned
- •Effect size matters more than p-values — Statistical significance ≠ practical importance
- •Longer studies are generally more reliable — Short-term biomarker changes may not reflect long-term outcomes
We grade evidence honestly so you can calibrate your confidence appropriately.
Research Library
In-depth analysis of foundational studies with translated summaries
Showing studies cited on: Physical Signs of IR
Showing 4 studies
Cohort Study
B
Rasi 2007: Skin Tags and Diabetes
Rasi et al. • International Journal of Dermatology • 2007
Multiple skin tags indicate 3x higher diabetes risk; >30 tags = 52% diabetes
Insulin Resistancephysical signsskin tags+1 more
A
Dunaif 1997: PCOS and Insulin Resistance
Dunaif • Endocrine Reviews • 1997
PCOS involves profound insulin resistance; insulin drives ovarian androgen production
Insulin Resistancepcoshyperandrogenism+1 more
C
Relation of hair graying to coronary artery disease
ElFaramawy et al. • Egyptian Heart Journal • 2018
Hair whitening independently predicts CAD: OR 1.31 (95% CI 1.09-1.57, p=0.004); patients with CAD had significantly higher HWS (60.1% vs 32.1%, p<0.001)
CardiovascularMetabolic Syndrome
How We Use References
In Calculators
Primary thresholds come from Grade A sources. When Grade A evidence suggests a range rather than a single value, we present the range with context.
In Educational Content
We draw on Grades A-C for educational claims, clearly labeling evidence quality. Grade D and E content is marked as theoretical or practitioner-derived.
In Paradigm Frameworks
- Standard Medical: Grade A (established guidelines)
- Research Consensus: Grade A-B (outcome research)
- Metabolic Optimization: Grade B-E (intervention research + clinical consensus)
Related Pages
Evidence Grades
Grade A: High ConfidenceReplicated findings across multiple studiesGrade B: Good ConfidenceWell-designed single studiesGrade C: Moderate ConfidenceObservational data with consistent patternsGrade D: Emerging EvidenceMechanistic or theoreticalGrade E: Clinical ConsensusPractitioner consensus
Other Pages
This bibliography contains the research supporting Metabolicum's evidence-based approach.
Last comprehensive review: December 2025