Am. Cotterill et al., CHANGES IN SERUM IGF-I AND IGFBP-3 CONCENTRATIONS DURING THE IGF-I GENERATION TEST PERFORMED PROSPECTIVELY IN CHILDREN WITH SHORT STATURE, Clinical endocrinology, 48(6), 1998, pp. 719-724
OBJECTIVE Genotype and phenotype heterogeneity in patients with GH ins
ensitivity syndrome suggests that partial defects exist in the GH rece
ptor. Children with partial GH resistance would be expected to have sh
ort stature, elevated GH levels and relatively low levels of IGF-1 and
IGFBP-3. Provocation tests of the GH-IGF-I axis may help to identify
such children. The IGF-1 generation test in particular may demonstrate
impaired secretion of IGF-1 and IGFBP-3. This prospective study asses
ses the usefulness of the IGF-1 generation test in the identification
of short children with possible GH insensitivity. DESIGN Prepubertal c
hildren referred for assessment of short stature underwent a standard
GH provocation test followed by an IGF-1 generation test. SUBJECTS Thi
rty-seven prepubertal children (14 girls, 23 boys) with short stature
(height < 2nd centile UK standards 1990) aged 4.5-12.6 years were inve
stigated prospectively. METHODS Assessment included history, physical
examination, auxological observations (height, weight, bone age). GH p
rovocation tests (glucagon 15 mu g/kg i.m. or insulin 0.15 U/kg/i.v.)
was followed by an IGF-1 generation test (hGH 0.1 iu/kg/s.c. daily for
4 days). MEASUREMENTS GH was assayed during the provocation test. IGF
-1 and IGFBP-3 were measured at 0900h on day 0 and 4 of the IGF-1 gene
ration test.