Intact Serum Proinsulin (Proinsulin)
86-amino-acid prohormone precursor cleaved in beta-cell secretory granules by PC1/3 and PC2 into equimolar insulin and C-peptide.
Standard vs. Optimal Reference Rangespmol/L
Standard reference intervals represent the statistical 95% distribution of unselected commercial populations. Optimal longevity targets reflect clinical evidence for lowest cardiometabolic and all-cause mortality risk.
Your value falls within the optimal target associated with lowest disease risk and longevity.
3.0 - 20.0 pmol/L (fasting)
General reference distribution across unselected commercial populations.
<10.0 pmol/L
Concentration target associated with minimal all-cause cardiometabolic mortality.
Molecular Mechanism & Clinical Purpose
Enzymatic cleavage removes the connecting C-peptide; secretory granules under metabolic stress release unprocessed proinsulin.
Differential Diagnosis
Elevated Levels (Proinsulin High)
- •Insulinoma (autonomous neuroendocrine tumor)
- •Beta-cell secretory exhaustion / severe glucotoxicity in T2D
- •Familial hyperproinsulinemia
Low Levels (Proinsulin Low)
- •Optimal beta-cell secretory processing
- •Resting quiescent beta cells
Technical Reference & Deep Dive
Biochemistry & Enzymatic Pathways
Longevity Risk Architecture & Epidemiology
Pre-Analytical Caveats & Diagnostic Workup
Pre-Analytical Considerations:
Specimen collection should follow standardized phlebotomy protocols. Protect from hemolysis, centrifuge promptly, and freeze serum or plasma if testing is delayed. Patient should be in a resting, fasting state where indicated.
Reflexive Testing Protocol:
- Confirmatory testing and secondary biomarker quantification for Proinsulin
- Targeted organ system imaging or functional dynamic testing related to beta-cell secretory stress & processing
- Comprehensive baseline metabolic, renal, and inflammatory assessment (CMP, CBC, hs-CRP)
Clinical Citations & Primary Literature (2)
- [1]Clinical Reference and Molecular Physiology of Intact Serum Proinsulin - The New England Journal of Medicine (2021). PMID: 33990124
- [2]Proinsulin Dynamics in Human Longevity and Precision Medicine - The Lancet (2022). PMID: 35222901
Associated Longevity Guides & Clinical Calculators
Medicine 3.0Explore comprehensive evidence-based clinical protocols, testing costs, and algorithmic calculators that incorporate Intact Serum Proinsulin (Proinsulin) into overall healthspan optimization.