Somatomedin-C and growth in children with precocious puberty: a study of the effect of the level of growth hormone secretion.
This study was undertaken to investigate the role of GH secretion in the pubertal increase in plasma somatomedin-C (Sm-C) concentrations and its relation to growth in children with true precocious puberty (PP) and normal or deficient GH secretion. We studied 37 children (9 boys and 28 girls), divided into 3 groups according to their pubertal stages and their peak stimulated plasma GH concentration. Group I (n = 20) contained patients with PP and normal GH secretion. In group II (n = 8), PP was accompanied by GH deficiency. Group III (n = 9) patients were GH deficient and prepubertal. The mean plasma Sm-C (RIA) levels in groups I and II were 2.01 +/- 0.17 (+/- SEM) and 0.59 +/- 0.21 U/mL, respectively (P less than 0.001), and it was 0.09 +/- 0.01 U/mL in group III (P less than 0.001 compared to group II). The higher mean plasma Sm-C level in group II compared to that in group III could be related to a significantly higher GH response to arginine-insulin stimulation (P less than 0.02), although this value was in the hypopituitary range. The mean growth rate in group II (6.8 +/- 0.9 cm/yr) was also much higher than the rate in group III (1.9 +/- 0.5 cm/yr; P less than 0.001) and only slightly lower than that in group I (90 +/- 0.8 cm/yr; P less than 0.05). These data indicate that plasma Sm-C values are closely correlated with even small changes in GH secretion. The observed growth rates could, in general, be linked to plasma GH and Sm-C levels, as modulated by sex steroids, in these patients with precocious puberty.
Rappaport
R
R
INSERM U.30, Hôpital des Enfants-Malades, Paris, France.
Prevot
C
C
Brauner
R
R
D000293:Adolescent; D001827:Body Height; D002648:Child; D002675:Child, Preschool; D005260:Female; D012739:Gonadal Steroid Hormones / Q000502:physiology; D006128:Growth; D013006:Growth Hormone / Q000097:blood / Q000378:metabolism*; D006801:Humans; D007334:Insulin-Like Growth Factor I / Q000097:blood*; D008297:Male; D011629:Puberty, Precocious / Q000503:physiopathology*; D013002:Somatomedins / Q000097:blood*
D012739:Gonadal Steroid Hormones; D013002:Somatomedins; D007334:Insulin-Like Growth Factor I; D013006:Growth Hormone