INSULIN LIKE GROWTH FACTOR (IGF-I) – SOMATOMEDIN -C

Insulin-Like Growth Factor (IGF-I) – Somatomedin-C

What it is

The Insulin-Like Growth Factor (IGF-I), also known as Somatomedin-C, test measures the level of IGF-I in the blood. IGF-I is a hormone mainly produced in the liver in response to growth hormone (GH) stimulation. It plays a crucial role in bone growth, tissue repair, and overall development. Since IGF-I levels remain stable throughout the day, this test provides a reliable way to assess growth hormone activity.

Uses

This test is used to evaluate growth disorders in children and adults, diagnose conditions like acromegaly (GH excess) or growth hormone deficiency, and monitor treatment response in patients receiving GH therapy. It is also used to investigate delayed puberty, short stature, or unexplained changes in growth patterns.

Symptoms That May Lead to the Test

Doctors may recommend this test for children with unusually slow or fast growth, delayed puberty, or suspected growth hormone deficiency. In adults, it may be ordered if there are symptoms such as enlarged hands or feet, coarsened facial features, fatigue, joint pain, or suspicion of pituitary gland disorders.

Abnormal Results

High IGF-I Levels: May indicate acromegaly or gigantism, usually caused by a growth hormone-secreting pituitary tumor. It may also reflect excessive GH therapy.

Low IGF-I Levels: Can suggest growth hormone deficiency, pituitary dysfunction, chronic illness, malnutrition, or liver disease. Low levels in children may lead to short stature and developmental delays.

Risks

The test requires a standard blood draw, which carries minimal risks such as mild pain, bruising, or lightheadedness at the puncture site. Serious complications are very rare.