Description
IGF-I is a single chain polypeptide mainly produced by hepatocytes as well as many tissues of both epithelial and mesenchymal, origin during both foetal and adult life. IGFs are potent mitogens, capable of modulating epithelial cell kinetics by stimulatory effects on proliferation and inhibitory effects on apoptosis. They induce anabolic metabolism and stimulate DNA synthesis, cell proliferation and meiotic division. Growth hormone (GH) could act directly on many tissues, including cartilage and kidney, and produce IGF-I, which is crucial to the growth-promoting actions of GH, locally. In childhood, the GH-IGF axis plays an important role in controlling growth. In adults, raised levels of IGF-I are associated with a reduced risk of impaired glucose tolerance, favourable cardiovascular disease risk factors, and a lower incidence of coronary heart disease.
Indications
In contrast with serum GH levels, serum IGF-I levels show little fluctuation during the course of the day. Therefore, measurement of IGF-1 (and its binding protein IGFBP-3) may be used as an indirect indicator of GH-secretion. Reduced IGF levels can lead to GH resistance. Low levels of IGF-I is associated with liver disease and cirrhosis and correlate with liver dysfunction. Serum IGF-I levels are invariably elevated in active acromegaly. Pregnancy and late puberty are also associated with elevated serum IGF-I levels.
Sample Type, Quantity & Conditions
1 ml Serum 1 ml Heparinized Plasma Stability: 24 Hours at 2-8 °C 12 Months at -25 °C
Special Precautions
Avoid grossly haemolysed or grossly lipemic samples.
Normal Range
21-25 Years: 116 - 358 ng/mL 15.08 - 46.54 nmol/L 26-30 Years: 117 - 329 ng/mL 15.21 - 42.77 nmol/L 31-35 Years: 115 - 307 ng/mL 14.95 - 39.91 nmol/L 36-40 Years: 109 - 284 ng/mL 14.17 - 36.92 nmol/L 41-45 Years: 101 - 267 ng/mL 13.13 - 34.71 nmol/L 46-50 Years: 94 - 252 ng/mL 12.22 - 32.76 nmol/L 51-55 Years: 87 - 238 ng/mL 11.31 - 30.94 nmol/L 56-60 Years: 81 - 225 ng/mL 10.53 - 29.25 nmol/L 61-65 Years: 75 - 212 ng/mL 9.75 - 27.56 nmol/L 66-70 Years: 69 - 200 ng/mL 8.97 - 26.00 nmol/L 71-75 Years: 64 -188 ng/mL 8.32 - 24.44 nmol/L 76-80 Years: 59 - 177 ng/mL 7.67 - 23.01 nmol/L 81-85 Years: 55 - 166 ng/mL 7.15 - 21.58 nmol/L
