Your body needs growth hormone (GH) for important processes like growth, cell renewal/function, and metabolism of nutrients (e.g., sugars, fats and proteins). In acromegaly, the pituitary gland in the brain makes too much GH, which results in symptoms that can affect your quality of life and overall health.
Pituitary gland and pituitary hormones
The pituitary gland is a small, hormone-releasing gland that is about the size of a pea. The front part of the gland releases, or secretes, five types of hormones:
- Adrenocorticotropic hormone (ACTH)
- Thyroid-stimulating hormone (TSH)
- Gonadotropins (LH and FSH)
- Growth hormone (GH)
The back part of the pituitary gland secretes two types of hormones:
- Antidiuretic hormone (ADH)
GH is released in response to GHRH (growth-hormone-releasing hormone) secretion from another part of the brain, called the hypothalamus.
The pituitary gland is found above the bridge of the nose and in front of the ear in the centre of the head, protected by a bony seat called the sella turcica
When GH is secreted by the pituitary gland into the bloodstream, it makes the liver produce and release an important hormone called IGF-1 (insulin-like growth factor-1). IGF-1 has a role in the overall growth of bone and other organs of the body.
The hypothalamus produces another hormone called somatostatin. Somatostatin prevents, or inhibits, GH from being produced and released from the pituitary gland. In this way, somatostatin and GH balance each other out.
Dopamine is a hormone that is produced in the hypothalamus. It has a mild effect on lowering GH production and release from the pituitary gland.
In most people who have acromegaly, a benign tumour, or adenoma, in the pituitary gland causes acromegaly. The tumour makes and releases too much GH into the bloodstream causing many of the symptoms and signs.
Check out the true-2-me guest editorial on treatment Considerations for Acromegaly