Source / episode info

• **Episode:**308
• **Title:**Divine Intervention Episode 308 – The Floridly HY NBME Cortisol Podcast (+ 2CK/3 20 hr course reminder).
• **Published:**2021-04-20
• Source:Episode page

One-liner

This episode provides a comprehensive review of cortisol metabolism, covering both excess (Cushing's syndrome workup using LDDST/HDDST) and deficiency (adrenal insufficiency diagnosis via cosyntropin stimulation test), emphasizing the associated electrolyte abnormalities and autoimmune associations.

High-yield summary

• Cortisol Excess: Characterized by central obesity, skin hyperpigmentation (due to ACTH stimulating melanocytes via POMC/MSH), hypochylemia, and metabolic alkalosis due to mineralocorticoid receptor effects of excess glucocorticoids.
• Primary Adrenal Insufficiency (Addison's): Leads to hypotension, hyponatremia (via SIADH from high ADH), hyperkalemia, and normal anion gap metabolic acidosis because the deficiency affects both cortisol AND aldosterone production.
• Secondary/Tertiary AI: Aldosterone function is generally preserved, meaning electrolyte abnormalities are typically absent or mild compared to primary AI.
• Cushing's Workup: Requires measuring 24-hour urinary cortisol, late-night salivary cortisol, and performing a low-dose dexamethasone suppression test (LDDST). ACTH levels help localize the source (adrenal vs. pituitary/ectopic).
• Adrenal Insufficiency Diagnosis: The gold standard is administering cosyntropin (ACTH analog); failure of cortisol to rise confirms primary adrenal insufficiency.
• Autoimmune Association: Addison's disease often occurs as part of Autoimmune Polyglandular Syndrome Type 2 (APS II), classically associated with Hashimoto's thyroiditis and Type 1 Diabetes Mellitus, all linked by AIRE gene mutations.

Learning objectives

• Differentiate the pathophysiology and clinical presentation of primary vs. secondary/tertiary adrenal insufficiency, particularly regarding mineralocorticoid status.
• Interpret diagnostic testing for hypercortisolism (LDDST, 24h urinary cortisol, ACTH measurement).
• Correlate electrolyte abnormalities (Na+, K+, HCO3-) with mineralocorticoid deficiency in adrenal insufficiency.
• Recognize the autoimmune associations of Addison's disease (APS II triad) and associated genetic markers (AIRE).
• Understand the management principles for acute adrenal crisis, including stress dosing and replacement therapy.