Use As A Diagnostic Test
| Reference ranges for IGF-1 (in ng/mL) |
||||
|---|---|---|---|---|
| Age | Females | Males | ||
| 2.5th centile |
97.5th centile |
2.5th centile |
97.5th centile |
|
| 20 | 111 | 423 | 156 | 385 |
| 25 | 102 | 360 | 119 | 343 |
| 30 | 94 | 309 | 97 | 306 |
| 35 | 86 | 271 | 84 | 275 |
| 40 | 79 | 246 | 76 | 251 |
| 45 | 73 | 232 | 71 | 233 |
| 50 | 68 | 228 | 66 | 221 |
| 55 | 64 | 231 | 61 | 214 |
| 60 | 61 | 237 | 55 | 211 |
| 65 | 59 | 241 | 49 | 209 |
| 70 | 57 | 237 | 46 | 207 |
| 75 | 55 | 219 | 48 | 202 |
IGF-1 levels can be measured in the blood in 10-1000 ng/ml amounts. As levels do not fluctuate greatly throughout the day for an individual person, IGF-1 is used by physicians as a screening test for growth hormone deficiency and excess in acromegaly and gigantism.
Interpretation of IGF-1 levels is complicated by the wide normal ranges, and variations by age, sex, and pubertal stage. Clinically significant conditions and changes may be masked by the wide normal ranges. Sequential management over time is often useful for the management of several types of pituitary disease, undernutrition, and growth problems.
Read more about this topic: Insulin-like Growth Factor 1
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