Description
In normal healthy adults, spontaneous growth hormone (GH) secretion shows a diurnal pattern and is influenced by age and sex. More than 99% of GH is secreted in a pulsatile fashion. 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. Because of the variability in GH secretion over the day and the short half-life of GH (approximately 20 min) in the circulation, random GH measurements have only limited value for the differential diagnosis of GH disorders. See Also Insulin-Like Growth Factor 1, Serum
Indications
Random GH levels are of little no diagnostic value, The diagnosis of GHD is confirmed by a peak plasma GH level below ~20 mU/L (dependant on GH assay) to 1 or 2 provocative tests (dependant on diagnosis). Tests commonly used include insulin hypoglycaemia (insulin tolerance test), glucagon, clonidine and arginine.
Sample Type, Quantity & Conditions
1 ml Serum 1 ml Li-Heparin or K2, K3-EDTA Plasma Stability: 8 Hours at 15-25 °C 1 Day at 2-8 °C 28 Days at -20 °C
Special Precautions
Freeze only once. 12 Hrs fasting is required. Keep sample on ice, separate and freeze immediately. Avoid haemolyzed samples.
Normal Range
Male: ≤ 10 Years: 0.094-6.29 ng/mL 11-19 Years: 0.077-10.8 ng/mL 20-79 Years: < 0.030-2.47 ng/mL Female: ≤ 10 Years: 0.120-7.79 ng/mL 11-20 Years: 0.123-8.05 ng/mL 21-77 Years: 0.126-9.88 ng/mL
