This test may exhibit interference when sample is collected from a person who is consuming a supplement with a high dose of biotin (also termed as vitamin B7 or B8, vitamin H, or coenzyme R). It is recommended to ask all patients who may be indicated for this test about biotin supplementation. Patients should be cautioned to stop biotin consumption at least 72 hours prior to the collection of a sample.
3 - 4 days
Turnaround time is defined as the usual number of days from the date of pickup of a specimen for testing to when the result is released to the ordering provider. In some cases, additional time should be allowed for additional confirmatory or additional reflex tests. Testing schedules may vary.
0.2 mL (Note: This volume does not allow for repeat testing.)
Red-top tube or gel-barrier tube
Separate serum from cells. Transfer separated serum to a plastic transport tube. Please include the patient's age on the test request form.
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.
Malnutrition will cause low somatomedin-C levels in spite of normal amounts of circulating growth hormone. The Sm-C level does not distinguish pituitary dwarfism from constitutional delay of growth and development.2
Immunochemiluminometric assay (ICMA)
21 to 25
26 to 30
31 to 35
36 to 40
41 to 45
46 to 50
51 to 55
56 to 60
61 to 65
66 to 70
71 to 75
76 to 80
81 to 85
86 to 90
IGF-1 is a relatively small peptide (molecular weight 7647) that is tightly bound in serum to one of several high affinity binding proteins.1 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,2-6 management of disorders that lead to nutritional insufficiency, or catabolism,7-9 and monitoring both GH and IGF-1 replacement therapy. IGF-1 measurement may also have a role in the physiology of malignant disease.10,11
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.12 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.13 In total, 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).
|Order Code||Order Code Name||Order Loinc||Result Code||Result Code Name||UofM||Result LOINC|
|010363||IGF-1||2484-4||010369||Insulin-Like Growth Factor I||ng/mL||2484-4|
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