SERUM INSULIN-LIKE GROWTH-FACTORS (IGFS) AND IGF BINDING-PROTEIN-1, BINDING-PROTEIN-2, AND BINDING-PROTEIN-3 IN CHILDREN WITH CHRONIC-RENAL-FAILURE - RELATIONSHIP TO HEIGHT AND GLOMERULAR-FILTRATION RATE
B. Tonshoff et al., SERUM INSULIN-LIKE GROWTH-FACTORS (IGFS) AND IGF BINDING-PROTEIN-1, BINDING-PROTEIN-2, AND BINDING-PROTEIN-3 IN CHILDREN WITH CHRONIC-RENAL-FAILURE - RELATIONSHIP TO HEIGHT AND GLOMERULAR-FILTRATION RATE, The Journal of clinical endocrinology and metabolism, 80(9), 1995, pp. 2684-2691
Serum levels of insulin-like growth factor I(IGF-I), IGF-II, and IGF b
inding protein 1 (IGFBP-1), IGFBP-2, and IGFBP-3 were measured in 94 c
hildren with chronic renal failure (CRF). The results were compared wi
th their respective age-dependent normal ranges, and the relationship
with height and residual glomerular filtration rate (GFR) was examined
. Each IGF and IGFBP was quantified by specific RIA. Serum IGF-I and I
GF-IT levels were in the normal range throughout their entire childhoo
d in the vast majority of cases. The mean age-related IGF-I (0.07 +/-
0.14 SD score) and IGF-II levels (0.06 +/- 0.11 SD) were similar. Age-
related IGF-II but not IGF-I levels showed a weak: inverse linear corr
elation with residual GFRs (r = -0.24, P < 0.02). Mean age-related IGF
BP-1 serum levels (1.04 +/- 0.09 SD) were slightly elevated, whereas m
ean age-related serum IGFBP-2 levels (3.25 +/- 0.20 SD) and serum IGFB
P-3 levels (2.61 +/- 0.12 SD) were markedly elevated. Significant inve
rse correlations were found between GFRs and age-related IGFBP-1 (r =
-0.42, P < 0.001), IGFBP-2 (r = -0.56, P < 0.001), and IGFBP-3 (r = -0
.28, P < 0.005), but the increase in IGFBP-2 with declining GFR was re
latively more pronounced than the respective increase in IGFBP-1 and I
GFBP-3. The correlation between age-related IGF-I and relative height
in prepubertal children with CRF (n = 54, r = 0.43,P < 0.001) was lowe
r than in prepubertal controls (n = 68, r = 0.67, P < 0.001), and the
slope of the regression line was significantly less steep, indicating
that the normal relationship between IGF-I and height is disturbed in
CRF. The normal relationship between IGFBP-3 and height was disrupted
in CRF. Forward stepwise regression analysis revealed that height in C
RF is correlated with IGF-I and inversely correlated with IGFBP-2. We
conclude that the imbalance between normal IGFs and excessive IGFBP se
rum levels in CRF plays a pathogenic role in the growth failure of the
se children.