Serum Free Fatty Acids (Non-Esterified) (FFA)
Free fatty acids are unesterified hydrocarbon chains bound to albumin in plasma, released from adipose tissue via hormone-sensitive lipase (HSL) lipolysis.
Standard vs. Optimal Reference Rangesmmol/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.
0.10 - 0.90 mmol/L
General reference distribution across unselected commercial populations.
0.15 - 0.45 mmol/L (Fasting)
Concentration target associated with minimal all-cause cardiometabolic mortality.
Molecular Mechanism & Clinical Purpose
High fasting FFA flux to skeletal muscle and liver induces diacylglycerol (DAG) accumulation, activating novel PKC isoforms (PKC-theta and PKC-epsilon) that impair insulin receptor substrate (IRS-1) tyrosine phosphorylation.
Differential Diagnosis
Elevated Levels (FFA High)
- •Severe peripheral insulin resistance
- •Acute myocardial ischemia
- •Prolonged starvation
- •Cushing syndrome
Low Levels (FFA Low)
- •High insulinemia suppressing lipolysis (e.g. postprandial state)
Technical Reference & Deep Dive
Biochemistry & Enzymatic Pathways
Longevity Risk Architecture & Epidemiology
Pre-Analytical Caveats & Diagnostic Workup
Pre-Analytical Considerations:
Strict 10 to 12 hour overnight water-only fasting is mandatory for baseline metabolic quantification. Acute psychological stress, acute infectious illness, and sleep deprivation (<6 hours) transiently elevate cortisol and catecholamines, falsely elevating glycemic markers. For glucose and insulin testing, draw blood into sodium fluoride/potassium oxalate tubes or separate serum promptly within 30 minutes to prevent ongoing in vitro red blood cell glycolysis.
Reflexive Testing Protocol:
- Homeostatic Model Assessment of Insulin Resistance (HOMA-IR) and HOMA-Beta calculations
- Continuous Glucose Monitoring (CGM) 14-day wear to evaluate glycemic variability and postprandial excursions
- Fasting C-Peptide and high-sensitivity Troponin/hs-CRP to differentiate insulin resistance from beta-cell exhaustion
- Oral Glucose Tolerance Test (OGTT) with simultaneous 0, 30, 60, and 120-minute insulin assays
- Abdominal ultrasound or FibroScan to evaluate hepatic steatosis and non-alcoholic fatty liver disease (MASLD)
Clinical Citations & Primary Literature (1)
- [1]Free Fatty Acids in the Pathogenesis of Insulin Resistance and Lipotoxicity - Nature Reviews Endocrinology (2021). PMID: 34188750
Associated Longevity Guides & Clinical Calculators
Medicine 3.0Explore comprehensive evidence-based clinical protocols, testing costs, and algorithmic calculators that incorporate Serum Free Fatty Acids (Non-Esterified) (FFA) into overall healthspan optimization.