IGF-1

Keywords: IGF1, Insulin growth factor 1, Somatomedin C, Insulin-like growth factor

Specimen:

5 mL blood in a plain tube.

Method:

Immunoassay.

Reference Interval:

Varies with age, gender and pubertal status.

Adult: 13-50 nmol/L.

Application:

Diagnosis of acromegaly or gigantism.

Diagnosis of Laron dwarfism.

Investigation of Hypopituitarism.

Limited value in the assessment of growth hormone deficiency or nutritional status.

Interpretation:

Levels are increased in acromegaly, and the test is used in the initial assessment of patients, prior to a Growth hormone suppression test.

Its diagnostic value is limited at the time of puberty, during Malnutrition and with severe illness.

In Laron dwarfism growth hormone is not reduced but IGF-I is reduced.

Low IGF-I has been used as a test for protein malnutrition but interpretation is difficult in view of changes in plasma IGF-binding proteins.

Reference:

Brabant G. Eur J Endocrinol. 2003; 148:2: 15-20.