:Normal range
| (F:(mg/L | (M:(mg/L | (Age(y | (F:(mg/L | (M:(mg/L | (Age(y |
| 1.45-5.69 | 1.45-4.75 | 22-23 | 0.66-2.51 | 0.9-1.79 | 0-1 |
| 1.51-4.4 | 1.15-4.3 | 24-25 | 0.843.77 | 1.12-2.33 | 2-3 |
| 1.38-4.7 | 1.24-5.18 | 26-27 | 1.32-3.6 | 1.16-3.13 | 4-5 |
| 1.19-5.43 | 1.23-4.27 | 28-29 | 1.21-4.66 | 1.32-3.38 | 6-7 |
| 1.29-4.06 | 1.29-4.06 | 30-34 | 1.58-3.99 | 1.35-3.94 | 8-9 |
| 1.5-3.44 | 1.5-3.44 | 35-39 | 1.93-5.5 | 1.53-5.02 | 10-11 |
| 1.33-3.6 | 1.33-3.58 | 10-44 | 1.78-6.08 | 1.73-5.11 | 12-13 |
| 1.44-2.8 | 1.44-2.75 | 45-49 | 2.02-5.4 | 1.9-6.4 | 14-15 |
| 1.31-2.5 | 1.31-2.52 | 50-54 | 1.88-5.3 | 1.7-6.04 | 16-17 |
| 1.53-2.4 | 1.53-2.43 | 55-59 | 1.63-6 | 1.52-6.01 | 18-19 |
| 1.4-3.22 | 1.4-3.22 | 60-70 | 1.82-5.4 | 1.79-5.41 | 20-21 |
Comment: Use in Growth hormone deficiency, originally proposed as a convenient (because of long half – life) marker of GH activity in the diagnosis of GH deficiency, the clinical accuracy is some what less than ideal
Sample: 2 ml serum, fasting & freeze immediately