What is acromegaly?
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. Each satellite follows one part of this picture, and the route runs from cause to consequence to management. So where should a reader begin?
Where to start, and what each part explains
The disease is easier to follow once normal GH biology is clear, so the best place to start is Growth Hormone Physiology. The satellites are listed in learning order:
- 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 explains who develops the disease, why diagnosis is usually delayed by years, and how it affects survival.
- Clinical Manifestations of Acromegaly explains what chronic GH excess does over years: tumor mass effects, soft tissue and skeletal change, sleep apnea, and 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 explains 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.
How does a tumor of one cell type come to reach the whole body? The place to begin is how GH itself is made, released and sensed.