Acromegaly Flashcards
Definition
Acromegaly is a rare hormonal disorder characterized by excessive growth hormone (GH) production, most commonly caused by a benign tumor of the pituitary gland called an adenoma. These tumors produce excessive amounts of GH, leading to abnormal growth of bones, soft tissues, and organs.
Causes
Pituitary adenomas: These non-cancerous tumors account. They cause an overproduction of GH
Growth hormone-secreting tumors outside the pituitary gland: Rarely, tumors in other parts of the body, such as the lungs or pancreas, can produce GH and cause acromegaly.
Excessive GHRH production: Overproduction of growth hormone-releasing hormone (GHRH) by the hypothalamus can stimulate the pituitary gland to produce more GH. This can be caused by a hypothalamic tumor or other factors.
Genetic syndromes: In rare cases, genetic conditions such as multiple endocrine neoplasia type 1 (MEN1) or McCune-Albright syndrome can lead to acromegaly.
IGF-1 Insulin-like Growth Factor 1 (IGF-1) is a polypeptide hormone with a molecular structure similar to insulin. It plays a crucial role in growth, development, and anabolism in both children and adults. Here’s an overview of IGF-1’s functions, regulation, and clinical implications:
Causes
Pituitary adenomas: These non-cancerous tumors account. They cause an overproduction of GH
Growth hormone-secreting tumors outside the pituitary gland: Rarely, tumors in other parts of the body, such as the lungs or pancreas, can produce GH and cause acromegaly.
Excessive GHRH production: Overproduction of growth hormone-releasing hormone (GHRH) by the hypothalamus can stimulate the pituitary gland to produce more GH. This can be caused by a hypothalamic tumor or other factors.
Genetic syndromes: In rare cases, genetic conditions such as multiple endocrine neoplasia type 1 (MEN1) or McCune-Albright syndrome can lead to acromegaly.
Symptoms of acromegaly
Enlarged hands and feet
enlarged nose, protruding jaw, and enlarged forehead, enlarged tongue,lip
Thickened skin
Widely spaced teeth
Excessive sweating and body odor
Deepening of the voice due to enlarged vocal cords
Joint pain and stiffness
Limited joint mobility
Arthritis
Carpal tunnel syndrome, characterized by numbness, tingling, and weakness in the hand
Headaches: Headaches may occur due to the growth of the pituitary tumor, which can compress surrounding brain structures.
blurry vision, double vision, or reduced peripheral vision, may result from the tumor pressing on the optic nerves.
Sleep apnea: Obstructive sleep apnea, a condition characterized by pauses in breathing during sleep, is common in individuals with acromegaly due to enlarged soft tissues in the upper airway.
Hormonal imbalances: Excessive growth hormone (GH) and insulin-like growth factor-1 (IGF-1) production can lead to various hormonal imbalances, including:
Increased insulin resistance and the risk of developing type 2 diabetes
Irregular menstrual cycles in women
Erectile dysfunction in men
Galactorrhea, which is abnormal lactation from the breasts in both men and women
Cardiovascular issues: Long-term exposure to high GH levels can increase the risk of high blood pressure, heart disease, and heart failure.
Psychological symptoms: Patients with acromegaly may experience mood swings, irritability, anxiety, or depression due to hormonal imbalances and the impact of physical changes on their self-esteem and quality of life.
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Diagnosis
Diagnosis
Medical history and physical examination: The doctor will review the patient’s medical history, discuss symptoms, and perform a physical examination to check for characteristic signs of acromegaly, such as enlarged hands and feet or facial changes.
Blood tests: These include measuring growth hormone (GH) and insulin-like growth factor-1 (IGF-1) levels. High levels of GH and IGF-1 support a diagnosis of acromegaly. In some cases, a glucose suppression test or a GH-releasing hormone (GHRH) stimulation test may be conducted to assess GH levels.
Imaging studies: Magnetic resonance imaging (MRI) or computed tomography (CT) scans are used to identify a pituitary tumor or other potential causes of acromegaly.
Treatment
Surgery: Transsphenoidal surgery, a minimally invasive procedure, is often the first-line treatment for acromegaly caused by a pituitary tumor. The surgeon removes the tumor through the nose and sinuses, which usually leads to a rapid reduction in GH levels.
Medications: In cases where surgery is not an option or doesn’t completely cure acromegaly, medications may be prescribed. These include:
Somatostatin analogs (e.g., octreotide, lanreotide) to inhibit GH secretion
Dopamine agonists (e.g., cabergoline, bromocriptine) to reduce GH production
GH receptor antagonists (e.g., pegvisomant) to block GH action on tissues
Oral medications (e.g., pasireotide) to target specific signaling pathways
Radiation therapy: Radiation may be recommended if surgery and medications fail to control GH levels or a significant amount of tumor remains after surgery. This approach can take several years to show its full effect, and hormone-reducing medications are often prescribed in the meantime.
Monitoring: Regular follow-up appointments are essential to monitor GH and IGF-1 levels, assess treatment efficacy, and manage potential complications or side effects.
