Serum

Red top tube

Preferred Minimum: 1 mL serum from red top tube

Plasma

1 week upon receipt at reference laboratory

IGF-Binding Protein-3 (UOM mg/L)
Reference Ranges (mg/L) for IGF
Binding Protein-3 (IGFBP-3):

Age Units

1-7 days <0.7
8-15 days 0.5-1.4
16 days-1 year 0.7-3.6
2 years 0.8-3.9
3 years 0.9-4.3
4 years 1.0-4.7
5 years 1.1-5.2
6 years 1.3-5.6
7 years 1.4-6.1
8 years 1.6-6.5
9 years 1.8-7.1
10 years 2.1-7.7
11 years 2.4-8.4
12 years 2.7-8.9
13 years 3.1-9.5
14 years 3.3-10.0
15 years 3.5-10.0
16 years 3.4-9.5
17 years 3.2-8.7
18 years 3.1-7.9
19 years 2.9-7.3
20 years 2.9-7.2
21-30 years 3.4-7.8
31-40 years 3.4-7.0
41-50 years 3.3-6.7
51-60 years 3.4-6.9
61-70 years 3.0-6.6
71-80 years 2.5-5.7
81-85 years 2.2-4.5
>85 years No primary data
81-85 years: 2.2-4.5
Reference Ranges (mg/L) for IGF Binding
Protein-3 (IGFBP-3) by Pubertal (Tanner) Stage:

Females

Tanner I 1.2-6.4
Tanner II 2.8-6.9
Tanner III 3.9-9.4
Tanner IV 3.3-8.1
Tanner V 2.7-9.1

Males

Tanner I 1.4-5.2
Tanner II 2.3-6.3
Tanner III 3.1-8.9
Tanner IV 3.7-8.7
Tanner V 2.6-8.6

Insulin-like growth factor binging proteins bing IGF-I and IGF-II with high affinty but do not bind insulin. Of the 6 distinct IGF binding proteins structurally characterized at this time, IGFBP-3 has been shown to be the major carrier of the IGFs, transporting approximately 95% of the circulatig IGF-I and IGF-II.

IGFBP-3 is growth hormone (GH) responsive. Thus, levels are high in cromegaly and low in hypopituitarism, and levels increase in GH- deficient children after GH administration.

Other causes of short stature that result in reduced IGFBP-3 levels include poorly controlled diabetes. The IGFBP-3 assay is useful in assessing nutritional status, since IGFBP-3 decreases during both caloric and protein restriction.

Immunoassay

83519

See also:
Insulin Like Growth Factor Binding Protein I (IGFBP-1), Serum
Insulin Like Growth Factor I (IGF-I), Serum
Insulin Like Growth Factor II (IGF-II), Serum