Insulin-like Growth Factor- l
(IGF-I)
Sample type
Serum (Red-top tube or gel-barrier tube)
Uses
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Diagnosis of acromegaly and pituitary deficiency; preferable to GH because it is constant after eating and during the day
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Help determine optimum dosage of GH
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Screening other growth disorders
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Assessing nutritional status
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Monitoring effectiveness of nutritional repletion; a more sensitive indicator than prealbumin, transferrin index, or retinol-binding protein
Precautions
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.
Interfering factors
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Malnutrition or not eating (fasting) will affect your results.
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Age also affects your results, as both IGF-1 and GH decline after puberty.
Pre-analytical errors
1-Plasma specimen or Gross hemolysis
The corrective action
1-The sample must be rejected and another sample be obtained.
Post-analytical errors
1- reports were sent to the incorrect patient
2- write the wrong name in the report or the wrong results.
The corrective action
1-communication with patient, apologising for the error, and providing him with the correct report
2- If the report is not delivered to the patient and this error is discovered, the correct result or the correct name must be written, but if the report is delivered to the patient, you must communicate with him, apologise to him, and tell him that an error has occurred and replace it with the correct report.
Reference Range
Males:
0-11 months: 18-156 ng/mL
1 year: 14-203 ng/mL
2 years: 16-222 ng/mL
3 years: 22-229 ng/mL
4 years: 30-236 ng/mL
5 years: 39-250 ng/mL
6 years: 47-275 ng/mL
7 years: 54-312 ng/mL
8 years: 61-356 ng/mL
9 years: 67-405 ng/mL
10 years: 73-456 ng/mL
11 years: 79-506 ng/mL
12 years: 84-551 ng/mL
13 years: 90-589 ng/mL
14 years: 95-618 ng/mL
15 years: 99-633 ng/mL
16 years: 104-633 ng/mL
17 years: 107-615 ng/mL
18-22 years: 91-442 ng/mL
23-25 years: 66-346 ng/mL
26-30 years: 60-329 ng/mL
31-35 years: 54-310 ng/mL
36-40 years: 48-292 ng/mL
41-45 years: 44-275 ng/mL
46-50 years: 40-259 ng/mL
51-55 years: 37-245 ng/mL
56-60 years: 34-232 ng/mL
61-65 years: 33-220 ng/mL
66-70 years: 32-209 ng/mL
71-75 years: 32-200 ng/mL
76-80 years: 33-192 ng/mL
81-85 years: 33-185 ng/mL
86-90 years: 33-179 ng/mL
> or =91 years: 32-173 ng/mL
Females:
0-11 months: 14-192 ng/mL
1 year: 23-243 ng/mL
2 years: 28-256 ng/mL
3 years: 31-249 ng/mL
4 years: 33-237 ng/mL
5 years: 36-234 ng/mL
6 years: 39-246 ng/mL
7 years: 44-279 ng/mL
8 years: 51-334 ng/mL
9 years: 61-408 ng/mL
10 years: 73-495 ng/mL
11 years: 88-585 ng/mL
12 years: 104-665 ng/mL
13 years: 120-719 ng/mL
14 years: 136-729 ng/mL
15 years: 147-691 ng/mL
16 years: 153-611 ng/mL
17 years: 149-509 ng/mL
18-22 years: 85-370 ng/mL
23-25 years: 73-320 ng/mL
26-30 years: 66-303 ng/mL
31-35 years: 59-279 ng/mL
36-40 years: 54-258 ng/mL
41-45 years: 49-240 ng/mL
46-50 years: 44-227 ng/mL
51-55 years: 40-217 ng/mL
56-60 years: 37-208 ng/mL
61-65 years: 35-201 ng/mL
66-70 years: 34-194 ng/mL
71-75 years: 34-187 ng/mL
76-80 years: 34-182 ng/mL
81-85 years: 34-177 ng/mL
86-90 years: 33-175 ng/mL
> or =91 years: 25-179 ng/mL