Acromegaly is a rare, chronic disorder caused by excessive growth hormone (GH). In almost all cases the source is a somatotrope adenoma: a tumor of the GH-producing (somatotrope) cells of the anterior pituitary gland. The excess acts in two directions at once: the tumor itself presses on the structures around the sella, while GH and its downstream mediator, insulin-like growth factor 1 (IGF-1), act on tissues throughout the body over years. The disease is easier to follow once normal GH biology is clear, so the best place to start is Growth Hormone Physiology; from there the route runs from cause to consequence to management.
- Growth Hormone Physiology explains how GH is built, released and sensed, and how its main downstream product, IGF-1, is made.
- Pathophysiology of Growth Hormone Hypersecretion explains how a pituitary adenoma produces GH excess, which adenoma subtypes and genetic alterations are involved, and which rare non-pituitary causes and familial syndromes can also lead to acromegaly.
- Epidemiology and Natural History of Acromegaly covers who develops the disease, why the diagnosis is usually delayed by years, and how it affects survival.
- Clinical Manifestations of Acromegaly describes what chronic GH excess does over years, from tumor mass effects and soft tissue and skeletal change to sleep apnea, musculoskeletal, neurological, metabolic, organ and neoplastic complications.
- Cardiovascular Complications of Acromegaly explains why the heart and vessels are the system most affected, and how hypertension and acromegalic cardiomyopathy develop.
- Diagnosis and Treatment of Acromegaly covers how the condition is recognized and confirmed with IGF-1 and the oral glucose tolerance test, how the pituitary is imaged, and how it is managed with surgery, radiotherapy and pharmacological therapy.