Adrenal Glands and Their Functions

Adrenal Glands

• Adrenal glands are endocrine glands found above the kidneys
• Each gland has an outer cortex and an inner medulla
• The cortex produces steroid hormones
• The medulla produces hormones like epinephrine (adrenaline) and norepinephrine (noradrenaline)
• Other hormones produced include glucocorticoids (cortisol), mineralocorticoids (aldosterone), and sex hormones

Pituitary Adrenal Axis

• The pituitary adrenal axis regulates adrenal cortex secretions
• It involves the hypothalamic hormone Corticotropin Releasing Hormone (CRH), the pituitary hormone Adrenocorticotropic Hormone (ACTH), and adrenal cortex hormones (mainly cortisol)
• Cortisol secretion is dependent on ACTH levels
• Cortisol levels peak in the morning and are lowest at night
• Sleep-wake patterns can disrupt this diurnal variation

Effects of Cortisol

• Increases blood glucose levels (gluconeogenesis)
• Controls carbohydrate, protein, and fat metabolism
• Enhances brain function (memory, concentration, and intellectual performance)
• Increases red blood cell production
• Decreases fibroblastic activity
• Inhibits osteoblast activity and lowers bone formation
• Decreases certain immune cells (eosinophils, basophils, monocytes, and lymphocytes)
• Has anti-inflammatory and anti-allergic effects
• Decreases capillary permeability
• Decreases inflammatory mediators
• Stabilizes lysosomal membrane

Adrenal Cortex Insufficiency

• Etiology: Congenital or acquired (primarily Addison's disease or secondary to pituitary insufficiency or exogenous steroid therapy)
• Addison's Disease: Adrenal cortex insufficiency (atrophy) causing cortisol and aldosterone deficiency
• Etiology (causes): Autoimmune disease, tuberculosis, hemorrhage, histoplasmosis, malignancy
• Clinical Features (Low Aldosterone): Sodium and water depletion, reduced extracellular volume, hypotension, retained potassium and hydrogen ions, and hyperkalemia and acidosis
• Clinical Features (Low Cortisol): Stimulation of pituitary gland increases ACTH levels, melanocyte stimulating activity increases skin pigmentation, oral melanin pigmentation, hypoglycemia, and weight loss and weakness
• Adrenal Crisis: Severe exacerbation of symptoms (hypotension, headache, dehydration, weakness, nausea, vomiting), precipitated by factors like surgery, stress, infection, trauma, or general anesthesia (GA).

Secondary Adrenal Cortex Insufficiency

• Patients on glucocorticoid therapy (anti-inflammatory and immunosuppressive drugs) may lead to adrenal atrophy
• Allergic diseases and autoimmune diseases (e.g., lupus, rheumatoid arthritis) are common reasons for glucocorticoid prescribing
• Adrenal atrophy can occur with long-term, low-dose or short-term high-dose steroids
• Patients with adrenal atrophy are unable to withstand stress, surgery, infection, or trauma and may suffer an adrenal crisis.

How to Avoid Adrenal Atrophy

• Alternate-day therapy allows the adrenal-pituitary axis to produce cortisol
• Single morning dose of steroid 1.5 hours after waking
• Supplementary steroid during stressful periods (surgery, trauma)
• Gradual withdrawal of steroids to allow adrenal function restoration
• Monitoring of patients on long-term steroid therapy

Exaggerated Normal Physiological Actions

• Carbohydrate Metabolism: Impairs glucose utilization, increases gluconeogenesis, potentially causing cortisol-induced diabetes
• Lipid Metabolism: Increase fat deposition (moon face, buffalo hump, central obesity)
• Protein Metabolism: Increase protein breakdown potentially leading to muscle weakness
• Lymphoid Atrophy: Fulminating infections and reactivation of latent infections

Adrenal Cortex Hyperfunction (Cushing's)

• Etiology: Cushing's disease (pituitary adenoma increases ACTH production stimulates the adrenal cortex), Cushing's syndrome (primary adrenal adenoma), and iatrogenic Cushing's syndrome (exogenous corticosteroids)
• Manifestations: Moon face, buffalo hump, central obesity, easy bruising and purple striae, muscle wasting in arms/legs, skin integrity issues, surface capillary fragility, and osteoporosis

Oral Manifestations

• Delayed growth, susceptible to infections, impaired wound healing
• Antibiotic coverage for dental procedures in patients on steroids

Contraindications to Corticosteroid Treatment

• Diabetes mellitus, osteoporosis, hypertension, glaucoma, viral infections, tuberculosis, pregnancy, lactation, patients on anticoagulants, and children
• Some of these conditions may be used with caution.