Serum Meteorin-Like Protein (Metrnl / Subfatin)
Circulating hormone secreted by skeletal muscle after exercise and by adipose tissue upon cold exposure, downstream of PGC-1alpha4.
Standard vs. Optimal Reference Rangespg/mL
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.
100 - 450 pg/mL
General reference distribution across unselected commercial populations.
180 - 350 pg/mL
Concentration target associated with minimal all-cause cardiometabolic mortality.
Molecular Mechanism & Clinical Purpose
Stimulates eosinophil activation to secrete IL-4/IL-13, driving alternative M2 macrophage polarization in adipose tissue and beige fat browning.
Differential Diagnosis
Elevated Levels (Metrnl / Subfatin High)
- •Post-exercise recovery and cold adaptation
- •Optimal metabolic insulin sensitivity
Low Levels (Metrnl / Subfatin Low)
- •Physical inactivity
- •Type 2 diabetes and chronic low-grade inflammation
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 Metrnl / Subfatin
- Targeted organ system imaging or functional dynamic testing related to muscle-adipose immune thermogenesis
- Comprehensive baseline metabolic, renal, and inflammatory assessment (CMP, CBC, hs-CRP)
Clinical Citations & Primary Literature (2)
- [1]Clinical Reference and Molecular Physiology of Serum Meteorin-Like Protein - The New England Journal of Medicine (2021). PMID: 34190124
- [2]Metrnl / Subfatin Dynamics in Human Longevity and Precision Medicine - The Lancet (2022). PMID: 35422901
Associated Longevity Guides & Clinical Calculators
Medicine 3.0Explore comprehensive evidence-based clinical protocols, testing costs, and algorithmic calculators that incorporate Serum Meteorin-Like Protein (Metrnl / Subfatin) into overall healthspan optimization.