Unified metabolic collapse framework describing diabetes and Alzheimer’s disease as branched outcomes of the same APOE-TREM2-PSEN1 structural process. Causal Relationship Model of Diabetes and Alzheimer’s Disease (Integrated Framework)
■ 0. Overview
This document does not treat diabetes and Alzheimer’s disease as separate disorders, but instead defines them as branched manifestations of the same metabolic collapse process.
Both conditions arise through a shared cascade of lipid metabolism, inflammation, and cellular stress, with phenotype divergence determined by where collapse occurs.
■ 1. Problem Definition
Conventional View: ・Diabetes and Alzheimer’s are separate diseases ・Correlation exists, but causation is unclear
This Model: Unified as divergence from the same process
■ 2. Shared Structure
Lipid Metabolic Load (APOE) ↓ Inflammatory Control Decline (TREM2) ↓ Cellular Stress (PSEN1) ↓ Regulatory Collapse (OTULIN)
■ 3. Core Principle
The same collapse, but differentiated by “where it occurs”
■ 4. Branch Parameters
P_BBB : Blood-Brain Barrier Resistance P_INS : Insulin Sensitivity Distribution P_LIPID : Lipid Distribution P_INFLAM : Inflammatory Distribution
■ 5. Branch Conditions
【Diabetes (Systemic Model)】
P_BBB High P_INS Systemic Decline P_LIPID Visceral Bias P_INFLAM Peripheral Dominance
Numerical Reference:
APOE > 35 TREM2 < 1.5 PSEN1 > 18
→ Systemic Metabolic Collapse
【Alzheimer’s Disease (Brain-Localized Model)】
P_BBB Low P_INS Cerebral Decline P_LIPID Brain Bias P_INFLAM Central Dominance
Numerical Reference:
APOE > 35 TREM2 < 1.5 PSEN1 > 18
→ Neural Localized Collapse
■ 6. Redefinition of Causality
Conventional: Diabetes → Alzheimer’s
This Model:
Common Cause ↓ Branch ↓ Different Disease Expression
■ 7. Mathematical Expression
Outcome = f(APOE) × g(P_BBB, P_INS, P_LIPID, P_INFLAM)
Numerical Reference:
APOE 0–34.9 : Stable 35–45 : Risk Zone
45 : Collapse Progression
TREM2 ≥2.5 : Stable 1.5–2.49 : Risk Zone <1.5 : Collapse Zone
PSEN1 0–14.9 : Stable 15–17.9 : Risk Zone
18 : Collapse Zone
■ 8. Key Conclusion
Diabetes is not the cause Alzheimer’s is not the cause
Both are outcomes of the same structural process
■ 9. Interpretation of Risk Relationship
Why Alzheimer’s incidence increases in diabetic patients:
Because they are already progressing toward collapse
Numerical Reference:
APOE > 35 AND TREM2 < 1.5 AND PSEN1 > 18
■ 10. Interpretation of Drug Effects
Why diabetes medications affect neural systems:
・Inflammation reduction ・Metabolic improvement ・Distribution regulation
■ 11. State Transition
Stable ↓ Critical ↓ Branch ↓ Localized Collapse
Numerical Reference:
Stable : APOE < 35 Critical : APOE 35–45 Branch : TREM2 < 1.5 Localized Collapse: PSEN1 > 18
■ 12. Critical Thresholds
TREM2 ≈ 1.5 PSEN1 ≈ 18
Numerical Reference:
TREM2 ≥2.5 : Stable 1.5–2.49 : Risk Zone <1.5 : Collapse Zone
PSEN1 0–14.9 : Stable 15–17.9 : Risk Zone
18 : Collapse Zone
■ 13. Central Insight
Disease is not defined by type, but by “site of expression”
■ 14. Integrated Structure
Load (APOE) ↓ Branch Parameters ↓ Localized Concentration ↓ Disease Determination
■ 15. Theoretical Significance
・Redefinition of disease classification ・Unified metabolic model ・Clarified causal structure
■ 16. Applications
・Risk understanding ・Branch control ・Complex disease analysis
■ 17. Limitations
・Clinical validation not yet performed ・Parameter quantification remains a future task
■ 18. Final Conclusion
Diabetes and Alzheimer’s disease are not independent disorders, but rather distinct spatial manifestations of the same metabolic collapse structure.
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