Plasma IGFBP-3 and its relationship with quantitative growth hormone secretion in short children.
OBJECTIVE
We assessed the relationship between serum IGFBP-3 levels with IGF-I and quantitative GH secretory status in poorly growing children.


METHODS
We studied the relationship between 24-hour integrated concentration of GH, peak GH to paired sequential stimulation tests, IGF-I and the IGFBP-3 serum levels.


METHODS
One hundred and two children (82 males, 20 females, age 11.7 +/- 2.7 years) with short stature (height -2.6 +/- 0.7 SDS) were studied.


METHODS
Quantitative GH secretory status was assessed by the 24-hour integrated GH and by response to arginine and insulin stimulation. GH, IGFBP-3 and IGF-I were measured by radioimmunoassay. To adjust for age and gender, IGFBP-3 levels were converted to SD score.


RESULTS
IGFBP-3 SDS was strongly correlated with IGF-I SDS (r = 0.64, P < 0.0001), and weakly with peak GH (r = 0.28, P < 0.0004), but not with the integrated GH concentration (r = 0.07, P < 0.46). IGFBP-3 SDS increased with pubertal maturation (P < 0.0001). There was no difference in mean IGFBP-3 SDS in subgroupings of the patients based on the results of their quantitative GH tests.


CONCLUSIONS
In short children, IGFBP-3 levels increase with puberty, are strongly correlated with IGF-I levels, weakly correlated with peak response to GH stimulation tests, but not correlated with integrated GH. Consequently, diagnostic classifications of patients based on quantitative measurements of GH secretion and IGFBP-3 differ.
Phillip
M
M
Department of Pediatric Endocrinology, University of Maryland School of Medicine, Baltimore.
Chalew
S A
SA
Kowarski
A A
AA
Stene
M A
MA
D000293:Adolescent; D002352:Carrier Proteins / Q000097:blood*; D002648:Child; D005260:Female; D006130:Growth Disorders / Q000097:blood* / Q000209:etiology; D013006:Growth Hormone / Q000097:blood / Q000172:deficiency / Q000378:metabolism*; D006801:Humans; D018969:Insulin-Like Growth Factor Binding Proteins; D007334:Insulin-Like Growth Factor I / Q000032:analysis; D008297:Male; D011627:Puberty / Q000097:blood; D012189:Retrospective Studies
D002352:Carrier Proteins; D018969:Insulin-Like Growth Factor Binding Proteins; D007334:Insulin-Like Growth Factor I; D013006:Growth Hormone