IGF-I and IGF-binding protein-3 measurements on filter paper blood spots in children and adolescents on GH treatment: use in monitoring and as markers of growth performance.
OBJECTIVE
In childhood an appropriate response to GH treatment is achieved by titration of growth response against dose administered, with careful observation for side-effects. In order to evaluate the potential use of IGF monitoring in children treated with GH, a cross-sectional study has been carried in 215 children and adolescents (134 with GH deficiency (GHD), 54 with Turner syndrome (TS) and 27 with non-GHD growth disorders) treated with GH for 0.2-13.7 years.


METHODS
IGF-I and IGF-binding protein-3 (IGFBP-3) were measured in ELISAs, using dried capillary blood collected onto filter papers. Results were expressed as the mean S.D. range (SDS). Values of either analyte < -2 or > +2 SDS were considered abnormal.


RESULTS
IGF-I and IGFBP-3 SDS were higher in the TS and non-GHD groups (mean +0.01 and +0.1 respectively) than in those with GHD (mean value -0.6). Nineteen per cent of the IGF-I values (13% low, 6% high) and 12% of IGFBP-3 values were abnormal (10% low, 2% high). Abnormalities, either low or high, were most common in the GHD group. There was a weak but significant relationship between change in height SDS over the Year up to the time of sampling in the whole group and IGF-I SDS. Satisfactory growth performance (+0.5>change in height SDS> -0.5) was found in those with high (7.2%), normal (60%) and low (9.3%) IGF-I levels. Overall, it was estimated that 26% of the tests would indicate that an adjustment to GH dose (up in 18% and down in 8%) could be considered.


CONCLUSIONS
From this cross-sectional study of IGF monitoring across a broad range of diagnoses and ages, it can be concluded that the majority of children on GH have normal levels of IGF-I and IGFBP-3, but 26% of tests could suggest that a change of GH dose should be considered. Regular monitoring of IGF-I and IGFBP-3 should be considered in any child on GH treatment.
Das
U
U
Academic Unit of Child Health, Royal Manchester Children's Hospital, Manchester M27 4HA, UK.
Whatmore
A J
AJ
Khosravi
J
J
Wales
J K H
JK
Butler
G
G
Kibirige
M S
MS
Diamandi
A
A
Jones
J
J
Patel
L
L
Hall
C M
CM
Price
D A
DA
Clayton
P E
PE
D000293:Adolescent; D001827:Body Height; D002648:Child; D002675:Child, Preschool; D003430:Cross-Sectional Studies; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006130:Growth Disorders / Q000097:blood* / Q000188:drug therapy*; D020249:Hormone Replacement Therapy; D019382:Human Growth Hormone / Q000172:deficiency / Q000627:therapeutic use*; D006801:Humans; D007223:Infant; D018972:Insulin-Like Growth Factor Binding Protein 3 / Q000097:blood*; D007334:Insulin-Like Growth Factor I / Q000378:metabolism*; D008297:Male
D018972:Insulin-Like Growth Factor Binding Protein 3; D019382:Human Growth Hormone; D007334:Insulin-Like Growth Factor I