Lab

Serum Cortisol

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Serum Cortisol, Blood Cortisol, Serum Cortisol Measurement, Cortisol

  • Physiology
  1. Cortisol is synthesized in the Adrenal Cortex, derived from Cholesterol
    1. See Cortisol Synthesis
  2. Cortisol secretion is stimulated by Adrenocorticotropic Hormone (ACTH) in response to stress
    1. See Pituitary Gland
  3. Cortisol functionality
    1. Mobilizes available energy sources (Glucose, fats, Amino Acids)
      1. Increases Serum Glucose by stimulating liver Gluconeogenesis and glycogenolysis
      2. Increases serum Fatty Acids by promoting lipolysis of adipose Triglyceride stores
      3. Increases blood Amino Acids by breaking down Proteins (outside liver)
        1. Within liver, Cortisol induces Protein synthesis
    2. Antiinflammatory activity
      1. Inhibit histamine release
      2. Inhibit Lymphocyte production
      3. Stabilize MacrophageLysosomes
    3. Increases gastric acid production
  4. References
    1. Goldberg (2014) Clinical Physiology, Medmasters, Miami, p. 138-9
  • Interpretation
  • Normal
  1. Cortisol 8 am: 4-19 mcg/dl
    1. Consider dynamic testing if early morning testing<13 mcg/dl
  2. Cortisol 4 pm: 2-15 mcg/dl
  • Interpretation
  • Increased
  1. Cushing's Disease
  2. Ectopic ACTH production
    1. Small-cell Lung Cancer
  3. Chronic Renal Failure
  4. Pregnancy
  • Interpretation
  • Decreased
  1. Primary or Secondary adrenocortical insufficiency
  2. Anterior pituitary dysfunction