Insulin-like Growth Factor-1 (IGF-1) With Z Score

Test ID:

704350

CPT code:

84305

Synonyms:

IGF-1

Clinical Use:

Results of the insulin-like growth factor-1 assay are to be used in conjunction with other clinical and laboratory data to assist the clinician in the assessment of growth disorders.

Test Information:

IGF-1 is a relatively small peptide (molecular weight 7647) that is tightly bound in serum to one of several high-affinity binding proteins. IGF-1 has approximately 50% sequence homology with proinsulin and has a number of biological activities similar to insulin. IGF-1 is a hormone that serves as the major effector of GH-stimulated somatic growth, as well as GH-independent anabolic responses in numerous tissues. IGF-1 has numerous growth-promoting effects, including mitogenic effects and the promotion of cartilage sulfation. Measurement of serum IGF-1 has been widely used in the diagnosis of disorders of GH secretion, management of disorders that lead to nutritional insufficiency or catabolism, and monitoring both GH and IGF-1 replacement therapy. IGF-I measurement may also have a role in the physiology of malignant disease.
The IDS iSYS IGF-1 assay conforms to the recommendations outlined in the recently published consensus statement on the standardization and evaluation of IGF-1 assays. The assay is calibrated to the WHO recombinant reference standard 02/254 for IGF-1. Reference intervals were developed through a multicenter study with samples from 12 cohorts from the USA, Canada, and Europe. A total of 15,014 subjects were tested (6697 males and 8317 females), ranging in ages from 0 to 94 years. Results are reported in mass units with reference intervals reflecting the central 95% interval (2.5 to 97.5 percentiles). Z scores, which reflect the number of standard deviations a given result is above or below the age-adjusted mean, are reported along with the IGF-1 concentration.