The role of IGF-I and IGFBP-3 measurements in the diagnostic work-up of short children
is established but remains controversial. Little information exists on the value of
IGFBP-2 measurements. Based on reference data established in 388 children we have
reinvestigated the issue, using data from 392 short children who underwent the same
diagnostic procedures between 1987 and 1998 (GHD, n = 187; non-GHD, n = 205, including
patients with ISS, n = 76; IUGR, n = 46; and TS, n = 83). In comparing IGF-I, IGFBP-3
and IGFBP-2 serum levels of GHD and ISS children with reference data, we calculated
the sensitivity, specificity, efficiency and positive predictive value for the diagnosis
of GHD. The overall sensitivity of the parameters was high, the rank order being as
follows: IGF-I >IGFBP-3 >IGFBP-2 (75, 67 and 62%, respectively). In contrast, the
specificity was relatively low: IGFBP-3 >IGFBP-2 >IGF-I (50, 50 and 32%, respectively).
The efficiency and positive predictive value of parameters was in the order of 40,
60 and 70–80%, respectively. In repeated measurements, the recorded basal levels of
IGF-I and IGFBP-3 showed an overall narrow range of variation. We conclude that the
determination of basal IGF parameters is, together with anthropometry and imaging
techniques, an indispensable tool for differentiating between GHD and ISS; and that
IGFBP-2 plays an additional role in this process.