Lecture 7.2 - Adrenal disorders

Cushing's Syndrome

• Chronic exposure to increased cortisol levels
• Benign pituitary disorder

Cushing's Syndrome vs Cushing's Disease

• Cushing's disease is a specific case of a benign ACTH secreting pituitary adenoma
• Cushing's syndrome is a general constellation of symptoms resulting from chronic exposure to increased cortisol levels
• Cushing's syndrome is more common than Cushing's disease
• Most commonly secondary to long-term treatment with glucocorticoids

Iatrogenic Cushing's Syndrome

• Caused by long-term treatment with glucocorticoid drugs (e.g. hydrocortisone, prednisone, prednisolone, dexamethasone)
• Used to treat inflammatory disorders, autoimmune conditions, and to suppress immune reaction to organ transplantation
• Glucocorticoids have anti-inflammatory and immunomodulatory effects
• Side effects of glucocorticoids are similar to the effects of higher cortisol levels
• Can also have mineralocorticoid effects (bind to the mineralocorticoid receptor)
• Important: Glucocorticoids should not be stopped suddenly, dosage should be reduced gradually

Signs and Symptoms

• Thin arms and legs with muscle weakness due to increased muscle proteolysis
• Weight gain and deposition of fat in abdomen, neck, and face
• Purple and wide striae on lower abdomen, upper arms, and thighs
• "Steroid diabetes" - secondary diabetes due to increased hepatic gluconeogenesis and muscle proteolysis
• Increased susceptibility to bacterial infections, poor wound healing, and acne
• Osteoporosis caused by calcium metabolism disturbances and loss of bone matrix protein
• Hypertension due to sodium and fluid retention caused by mineralocorticoid effects
• Psychologic symptoms - mental changes, depression
• Hypogonadism, menstrual disorders in women, hirsutism, and baldness

Clinical Effects and Diagnosis

• Cushing's syndrome mortality is >50% if not treated
• Death usually results from severe infection
• Growth ceases in children with Cushing's syndrome if not treated before epiphyses of the bones have sealed
• Clinical diagnosis, biochemical diagnosis, and radiological diagnosis to localise the problem
• Golden rule: clinical diagnosis, biochemical diagnosis, and radiological diagnosis

This quiz covers the difference between Cushing's syndrome and Cushing's disease, including their causes and symptoms. Learn about the effects of chronic cortisol exposure and benign pituitary disorders.