Before the Threshold: Hyperinsulinemia as a Candidate Modifiable Driver of β-Cell Exhaustion in Genetically Burdened, Normoglycemic Offspring of Patients With Type 2 Diabetes — A Translational Hypothesis and Prototype Risk Matrix for Trial Design
Abstract
Background. Type 2 diabetes mellitus (T2DM) is diagnosed at decompensation thresholds — fasting plasma glucose (FPG) ≥126 mg/dL or HbA1c ≥6.5% — that typically declare disease only after substantial β-cell loss. Normoglycemic offspring of parents with T2DM carry several-fold lifetime risk yet receive no structured surveillance. Hypothesis. In genetically burdened, normoglycemic individuals, chronic hyperinsulinemia may not be merely compensatory. Sustained secretory demand may itself injure the β cell through endoplasmic reticulum (ER) client overload with unfolded protein response dysregulation, mTORC1-mediated autophagy suppression, FoxO1 nuclear exclusion with identity erosion, and prohormone processing infidelity — a proposed feed-forward loop terminating in secretory failure. Framework. We present a prototype, pedigree-gated risk matrix in two configurations — an essential three-layer pathway (familial gatekeeper; triglyceride–glucose index and 1-hour oral glucose tolerance test glucose; clinical stigmata) and a full 0–10 score adding HOMA-IR and an optional fasting proinsulin:C-peptide module — with a provisional action threshold of ≥5.5. Every performance figure attached to this matrix is an explicit design specification for trial planning, not an observed result. Conclusion. The framework is deliberately hypothesis-generating: metformin as β-cell load reduction is positioned only within shared decision-making or the proposed BETA-SHIELD randomized trial; no component is ready for clinical adoption.
