Failure of IGF-I and IGFBP-3 to diagnose growth hormone insufficiency

H Mitchell, MT Dattani, V Nanduri… - Archives of disease in …, 1999 - adc.bmj.com
H Mitchell, MT Dattani, V Nanduri, PC Hindmarsh, MA Preece, CGD Brook
Archives of disease in childhood, 1999adc.bmj.com
BACKGROUND Growth hormone insufficiency (GHI) is diagnosed conventionally by short
stature and slow growth, and is confirmed by diminished peak GH response to a provocation
test. Insulin-like growth factor I (IGF-I) and IGF binding protein 3 (IGFBP-3) have previously
been considered individually OBJECTIVE To test the hypothesis that the combined analysis
of IGF-I and IGFBP-3 could act as a surrogate marker for the diagnosis of GHI. DESIGN
Reference ranges for IGF-I and IGFBP-3 were calculated using 521 normal individuals. A …
BACKGROUND
Growth hormone insufficiency (GHI) is diagnosed conventionally by short stature and slow growth, and is confirmed by diminished peak GH response to a provocation test. Insulin-like growth factor I (IGF-I) and IGF binding protein 3 (IGFBP-3) have previously been considered individually
OBJECTIVE
To test the hypothesis that the combined analysis of IGF-I and IGFBP-3 could act as a surrogate marker for the diagnosis of GHI.
DESIGN
Reference ranges for IGF-I and IGFBP-3 were calculated using 521 normal individuals. A retrospective analysis was performed on 318 children referred for investigation of short stature.
RESULTS
No significant difference was found between either the IGF-I or IGFBP-3 standard deviation scores (SDSs) in children with and without GHI. If the requirement were for both tests to be positive (< −2 SDS) for a diagnosis of GHI, then 99% of children without GHI would be correctly identified; however, the sensitivity of the test was only 15%.
CONCLUSIONS
Neither IGF-I nor IGFBP-3 alone is a marker for GHI. In addition, they cannot be used as an effective screening test in combination.
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