A. Bereket et al., GROWTH-HORMONE TREATMENT IN GROWTH-RETARDED CHILDREN WITH END-STAGE RENAL-FAILURE - EFFECT ON FREE DISSOCIABLE IGF-I LEVELS, Journal of pediatric endocrinology & metabolism, 10(2), 1997, pp. 197-202
Growth retardation in children with end-stage renal disease (ESRD) is
associated with normal to slightly low concentrations of insulin-like
growth factor (IGF)-I and increased concentrations of IGF-binding prot
eins (IGFBPs) in serum, Consequently, IGF-I bioactivity is reduced in
serum from uremic patients presumably due to a decrease in the concent
ration of free IGF-I, Improvement of linear growth with growth hormone
(GH) treatment of uremic children is thought to be due to increased I
GF-I/IGFBP ratio, thus resulting in increased free IGF-I levels during
treatment, The purpose of the present study was to determine whether
free/dissociable TGF-I levels are in fact low in uremic children and w
hether increased growth velocity during GH treatment is associated wit
h an increase in the free IGF-I concentration, Serum total and free/di
ssociable IGF-I concentrations were measured in 5 children with ESRD b
efore and during treatment with GH, and in control children matched fo
r age, pubertal status, and body mass index, Height velocity increased
from 3.7 +/- 1.0 cm/yr to 6.5 +/- 1.2 cm/yr with an increment in heig
ht SDS at the end of the first year of GH treatment, Free/dissociable
IGF-I concentrations tended to be lower in uremic children compared to
control children (3.0 +/- 0.3 vs 7.3 +/- 2.1 mu g/l, respectively). D
uring GH treatment, free/dissociable IGF-I levels increased significan
tly to 8.5 +/- 1.0 mu g/l at 3 months and 6.9 +/- 1.4 mu g/l at 6-24 m
onths, p<0.05 compared to pretreatment. Total IGF-I levels were 243 +/
- 18 mu g/l in children with ESRD before treatment and these values al
so increased during GH treatment (740 +/- 114 mu g/l at 3 months and 4
42 +/- 44 mu g/l at 6-24 months, p<0.05, compared to pretreatment), To
tal IGF-I concentration in the control group was 439 +/- 114 mu g/l, T
hese results support the hypothesis that growth retardation in childre
n with chronic renal failure is associated with a reduction in the con
centration of free, biologically available IGF-I, and that increased g
rowth velocity during GH treatment of these children is associated wit
h restoration of free IGF-I concentrations.