Chapter 93: Adrenal Gland Disorders

KEY CONCEPTS

• Glucocorticoid secretion from the adrenal cortex is stimulated by adrenocorticotropic hormone (ACTH) or corticotropin that is released from the anterior pituitary in response to the hypothalamic-mediated release of corticotropin-releasing hormone (CRH).

• To ensure the proper treatment of Cushing syndrome, diagnostic procedures should (1) establish the presence of hypercortisolism and (2) discover the underlying etiology of the disease.

• The rationale for treating Cushing syndrome is to reduce the morbidity and mortality resulting from disorders such as diabetes mellitus, cardiovascular disease, and electrolyte abnormalities.

• The treatment of choice for both ACTH-dependent and ACTH-independent Cushing syndrome is surgery. Pharmacologic agents are reserved for adjunctive therapy, refractory cases, or inoperable disease.

• Pharmacologic agents that may be used to manage the patient with Cushing syndrome include steroidogenesis inhibitors, adrenolytic agents, neuromodulators of ACTH release, and glucocorticoid-receptor blocking agents.

• Spironolactone, a competitive aldosterone-receptor antagonist, is the drug of choice in bilateral adrenal hyperplasia (BAH)–dependent hyperaldosteronism.

• Addison’s disease (primary adrenal insufficiency) is a state of deficiency in cortisol, aldosterone, and various androgens due to the loss of function in all regions of the adrenal cortex.

• Secondary adrenal insufficiency usually results from exogenous steroid use, leading to hypothalamic–pituitary–adrenal (HPA)–axis suppression followed by a decrease in ACTH release, and low levels of androgens and cortisol.

• Virilism results from the excessive secretion of androgens from the adrenal gland and often manifests as hirsutism in females.

Patient Care Process for Cushing Syndrome

Collect

• Patient characteristics (eg, age, sex, pregnant)

• Patient medical history (personal and family)

• Social history (eg, tobacco/ethanol use)

• Iatrogenic causes of Cushing syndrome: current medications including corticosteroids (all routes, past and present), medroxyprogesterone acetate, megestrol acetate, gamma-hydroxybutyic acid, CYP3A4 inhibitors and inducers

• Objective data

  • Blood pressure, heart rate, body mass index

  • Test for hypercortisolism: 24-hour UFC, midnight plasma cortisol, late-night salivary cortisol, or low-dose dexamethasone suppression test

  • Follow-up diagnostic tests to differentiate etiologies (see Fig. 93-4)

Assess

• Presence of Cushing syndrome complications:

  • Metabolic: impaired glucose metabolism, dyslipidemia

  • Cardiovascular: hypertension, vascular damage, thrombosis, hypokalemia

  • Immunologic: bacterial, fungal, and viral infections; rebound autoimmunity Musculoskeletal: osteopenia/osteoporosis, myopathy

  • Neuropsychiatric: depression, anxiety, bipolar disorder

  • Reproductive: decreased libido, hypogonadism (men), menstrual irregularity (women)

  • Dermatologic: hirsutism, alopecia, hyperhidrosis

• Physical exam: Peripheral obesity, fat accumulation (Buffalo Hump), rounded face (moon face), striae, ecchymosis, hyperpigmentation, acanthosis nigricans, acne, and thin skin

• Current medications that may contribute to or worsen Cushing syndrome.

• Results of follow-up diagnostic testing for etiology (see Fig. 93-4, and Tables 93-2 and 93-3)

• Ability/willingness to pursue surgical/chemotherapeutic (if indicated) versus medical management

Plan^*

• Ensure proper administration of necessary corticosteroid therapy; discontinue unnecessary corticosteroid therapy, with taper if HPA axis integrity is suspect

• Nondrug options for endogenous Cushing syndrome, depending on etiology: surgery, chemotherapy, irradiation, postoperative ...