Examinations
Examinations
Insulin-like growth factor 1 (IGF-1) is one of the best markers for evaluating growth hormone synthesis. A normal level of somatomedin in blood plasma rules out growth hormone deficiency.
This hormone is called insulin-like because, like insulin, it stimulates glucose uptake by muscles and adipose tissue. IGF-1 is primarily synthesized in the liver and plays a crucial role in growth, development, and the proper functioning of many cells. One of its most important effects is stimulating longitudinal bone growth. Circulating IGF-1 also enhances insulin sensitivity, and its deficiency is associated with insulin resistance. Currently, the role of IGF-1 in carcinogenesis is under investigation.
- A venous blood sample is required for testing.
- The test should be taken after 8–14 hours of fasting.
- It can also be taken 4 hours after a light meal.
- Avoid emotional and physical stress before the test.
- Alcohol consumption should be avoided.
- ⚠️ The test should not be performed during an acute illness.
- Diagnosis of growth disorders
- Monitoring treatment of acromegaly and dwarfism
- Assessment of metabolic changes
Causes of Increased IGF-1 Levels:
- Acromegaly
- Cushing's syndrome
- Renal failure
- Use of certain medications (androgens, clonidine, dexamethasone)
Causes of Decreased IGF-1 Levels:
- Dwarfism
- Hypopituitarism
- Hypothyroidism
- Fasting
- Anorexia
- Emotional deprivation syndrome
- Laron syndrome (Laron dwarfism)
- Liver cirrhosis and other hepatocellular diseases
- Acute illnesses
- Use of estrogen, tamoxifen