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ADRENAL INSUFFICIENCY. Background. 1855 Thomas Addison-clinical syndrome characterized by wasting and hyperpigmentation Cause as destruction of the adrenal glands 1994 life-saving steroid replacement therapy developed-Kendall, Sarett & Reichstein. Epidemiology. Primary & Secondary
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Background • 1855 Thomas Addison-clinical syndrome characterized by wasting and hyperpigmentation • Cause as destruction of the adrenal glands • 1994 life-saving steroid replacement therapy developed-Kendall, Sarett & Reichstein
Epidemiology • Primary & Secondary • Chronic primary: 93-140/million, incidence 4.7-6.2/million (white, 4th decade, women > men) • Secondary: 150-280/million, peak 6th decade, women > men) • Therapeutic steroid use-most common cause
Introduction • Medulla secretes epinephrine and norepinephrine into adrenal veins when stimulated • Cortex secretes steroids regulating metabolism, vascular tone, cardiac contractility, TBW/Na/K balance, androgenic function (GFR: aldosterone/mineralocorticoids, cortisol/glucocorticoids, testosterone/androgenic steroids)
Physiology • Cyclic secretion controlled by time of day, HPA axis, renin-angiotensin system, serum potassium levels • Stress increases basal glucocorticoid and mineralcorticoid levels 5-10 fold • Occurs within minutes
Definitions • Basal failure results in adrenal insufficiency • Leads to insidious wasting disease • Stress failure results in adrenal crisis • Life-threatening • Absence of glucocorticoids is most critical
Glucocorticoids • Regulate fat, glucose, protein metabolism • Catecholamine and b-adrenergic receptor synthesis • Maintain vascular tone and cardiac contractility • Control endothelial integrity/vascular permeability
Glucocorticoids • Cortisol • Controlled by HPA axis • Hypothalamus CRH and arginine vasopressin in circadian rhythm (max 2-4am) • Anterior Pituitary ACTH • Adrenal cortex cortisol • Peak @ 8am; declines throughout day
Glucocorticoids • Cortisol • 20-25mg produced daily (non-stressed) • 5-10% free and physiologically active • Remainder bound to cortisol-binding globulin • Becomes uncoupled in times of stress • Negatively feeds back to control hypothalamus • Role in adrenal insufficiency
Mineralcorticoids • Regulated via renin-angiotensin system & serum potassium levels • Diminished GFR juxtaglomerular apparatus release of prorenin • Aldosterone release Na & H2O resorption at distal tubules (K is lost) • Minor hyperkalemia can stimulate aldosterone secretion directly
Adrenal Androgens • Controlled by ACTH • Diurnal pattern (like cortisol) • Significant source of androgens in females • Can cause signs/symptoms seen in adrenal insufficiency
Adrenal Insufficiency • Primary = failure of adrenal glands • Secondary = failure of HPA axis • Usually due to chronic exogenous glucocorticoid administration • pituitary failure • Tertiary = Hypothalamic dysfunction
Primary Adrenal Insufficiency • Loss of all three types of adrenal steroids • 90% of glands must be destroyed to manifest clinically • High functional reserve • Adrenoleukodystrophy = X-linked inherited d/o of very-long-chain fatty acid metabolism • Progressive neurological symptoms from white matter demyelination (mutation of the ABCD 1 gene encoding for the peroxisomal ALD protein) • Cerebral: 50%, early childhood, rapid progression • Adrenaomyeloneuropathy: 35% early adulthood, slow progression restricted to spinal cord and peripheral nerves • Accumulation of VLCFA • 15% adrenal insufficiency precedes onset of neurological symptoms
Primary Adrenal Insufficiency • Addison disease =m.c. autoimmune d/o (40% male predominance; APS 60% female predominance) • Thrombosis/hemorrhage • Sepsis, DIC, antiphospholipid syndrome • Infiltrative diseases • Bilateral cancer metastasis • Amyloidosis, hemosiderosis (rare) Drug-induced -mitotane, aminoglutethimide, etomidate, ketoconazole, metyrapone
Primary Adrenal Insufficiency • TB = m.c. infectious cause worldwide • HIV = m.c. infectious cause in US • 50% have degree of destruction • Only 5% have clinical symptoms of A.I. • CMV infection, ketoconazole use, macrophage-released cytokines are risk factors Fungal infection =m.c. in immunocompromised patients (cryptococcosis, histoplasmosis, coccidiomycosis) CAH = 21-OH def, 11b-OH def, 3b-HSD type 2 def, 17a-OH def (ambiguous genitalia, virilization, hypertension etc.)
AutoimmumePolyglandular Syndrome (APS) • Classification (Betterle C et al. Endocr Rev 23: 237, 2002):
APS type I • APECED (autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy)-15% • Adrenal insufficiency, hypoparathyroidism, chronic mucocutaneouscandidiasis (at least 2) • Onset during childhood • Associated with other autoimmune disorders • Childhood alopecia 40%, chronic active hepatitis 20%, and malabsorption 15% • Mutation in autoimmune regulator (AIRE) gene which modulates the transcription of peripheral self-antigens in the thymus presented by HLA molecules to mature T cells, autosomal recessive • Diagnosis: functional testing, interferon omega (100% sensitive), AIRE • Survey/Therapy: clinically q6m particular attention to AI development and replacement hormone, regular monitoring of calcium, antifungal (ketoconazole, fluconazole, ampho B, bx), blood smear for Howell-Jolly bodies; if asplenic: immunizations properly
APS type 2 • Most frequently seen • Adrenal insufficiency AND autoimmune thyroiditis (Schmidt’s), and/or DMI (Carpenter’s) • Other autoimmune diseases-vitiligo, chronic atrophic gastritis, celiac disease, pernicious anemia, myasthenia gravis • Autosomal dominant with incomplete penetrance; females > males; 1:20K prev • Strong association with HLA-DR/DQ/DP and CTLA-4, MICA5.1, PTPN22
APS type 3 and 4 • APS type 3: AITD + other autoimmune disease processes (does not involve adrenal insufficiency or hypoparathyroidism) Sub-types: A, B, C, D based on various combinations of diseases; particularly sub-type 3D (frequent association with SLE/RA, systemic sclerosis, sjogren etc.) • APS type 4: two or more autoimmune diseases that do not meet criteria for 1, 2 or 3
Secondary Adrenal Insufficiency • HPA axis failure • deficiency of glucocorticoids and adrenal androgens • mineralcorticoids are unaffected • #1 cause=chronic exogenous glucocorticoid • suppresses diurnal CRH/AV release • both time- and dose-related • reversible • recovery may take up to a year
Secondary Adrenal Insufficiency • Less common causes • Postpartum necrosis (Sheehan syndrome) • Adenoma hemorrhage(s) • Pituitary destruction from head trauma • Pituitary/other tumors (craniopharyngioma, meningioma etc.) • Irradiation, lymphocytic hypophysitis, congenital syndromes (POMC defect/def, combined pituitary hormone def), infiltration (TB, fungal, histiocytosis X, sarcoidosis) • typically have associated focal neurological changes, visual deficits, diabetes insipidus or panhypopituitarism
Secondary Adrenal Insufficiency MYTHBUSTERS! • Short course (2-3 weeks) is unlikely to suppress the HPA axis • Daily doses of prednisone 5mg or less are unlikely to cause secondary insufficiency
Chronic Insufficiency CLINICAL PRESENTATION • Nonspecific • Fatigue, weakness (74-100%), anorexia, weight loss (56-1--%), loss of libido • Neurological • Headaches, visual changes, diabetes insipidus • Gastrointestinal (56%) • Pain, nausea, vomiting, diarrhea
Chronic Insufficiency CLINICAL PRESENTATION • Hypotension/Orthostasis (59-88%) • Cachexia • Thin axillary and pubic hair in women • Hypoglycemia • Normocytic anemia, lymphocytosis, eosinophilia • Hypercalcemia (6-41%) due to increased GI absorption and decreased renal excretion • Muscle & joint pain
Chronic Insufficiency CLINICAL PRESENTATION • Hyperpigmentation (92-96%) • Pressure points, axillae, palmar creases, perineum, oral mucosa • Usually seen early in primary AI • Caused by enhanced stimulation of skin MC1-receptor by ACTH & other POMC-related peptides • Pallor out of proportion to anemia (alabaster-colored skin) • Seen in secondary AI
Chronic Insufficiency CLINICAL PRESENTATION • Hyponatremia (88-96%) • Primary = lack of aldosterone & Na wasting • Secondary = vasopressin secretion (dilutional effect) • Hyperkalemia (52-64%) • Only occurs in primary • mild with associated azotemia & met acidosis
DHEA deficiency: Major precursor of sex-steroid synthesis Loss results in pronounced androgen deficiency in women (loss of axillary/pubic hair, dry skin, reduced libido) Potential antidepressant properties May contribute to the impairment of wellbeing
Adrenal Crisis CLINICAL PRESENTATION • Life-threatening emergency • May be primary or secondary • HYPOTENSION • Typically resistant to catecholamine and IVF resuscitation
Adrenal Crisis CLINICAL PRESENTATION • Abrupt adrenal failure usually from gland hemorrhage or thrombosis • Anticoagulation • DIC • Sepsis (Waterhouse-Friderichsen syndrome) • Usually have abdominal and flank pain • Can resemble ruptured AAA!!!
Adrenal Crisis CLINICAL PRESENTATION • Catastrophic HPA axis failure • Head trauma • Hemorrhage of pituitary adenoma • Post-partum herniation (Sheehan syndrome) • Usually neurological deficits, headaches, visual field cuts and diabetes insipidus
Diagnosis • Short corticotropinstim test • Get baseline level • Inject 250mcg cosyntropin (IV or IM) • Measure plasma cortisol level in 60 minutes • Excluded if basal or test level is > 18mcg/dL • Plasma cortisol levels between 8am-9am • Level < 3 mcg/dL rules IN • Level > 19 mcg/dL rules OUT Overnight metyrapone test (inhibits 11b hydroxylase) 30mg/kg max 3 g administered with a snack at midnight Healthy-deoxycortisol increases, cortisol < 8 Secondary AI- 11-deoxycortisol < 7 at 8 am
Low dose corticotropin test • 1mcg ACTH • More sensitive • Need to dilute test amount from commercially available 250 mcg ACTH • Still results in hormone conc. greater than those for maximum cortisol release
Burch W. EndocrPract 17:591, July/Aug 2011Using bedtime and early morning urine cortisol/creatinine (ng/ml) ratios to evaluate pituitary adrenal function in an office practice • Diurnal pattern (7-fold increase PM to AM P<0.0001) in 26 healthy controls (16 to 92), respective ranges 12.5-19 pm and 65-118 am; and 131 outpts without endocrine disease (but with fatigue, malaise, inability to lose weight) AM/PM ratio=7; change AM-PM=76 • 11 Cushing’s syndrome: loss of diurnal pattern with pm urine level 127 and AM/PM ratio 1.16 consistent with known diagnosis • 11 hypopit pts: little to no increase in am compared to pm urine voids • Conclusions: AM/PM cortisol/creatinine ratios may offer a convenient outpatient method for assessing pituitary-adrenal function
Special situations • Standard short ACTH test 4-6 weeks after pituitary surgery • In critically ill patients • Random sample serum cortisol and plasma ACTH follow by immediate hydrocortisone administration