Abstract
Association of delayed puberty and low serum IGF-I is observed in GH deficiency and chronic malnutrition, while advanced central puberty and high IGF-I is seen in children after long time exposure to high levels of sex hormones(SH). While some workers have reported a decrease of serum IGF-I during therapy of precocious puberty (PP)with GnRHa, others have shown no change. We have studied 7 children with PP, 4 with central PP(2 boys aged 3.5 and 7.5 y, 2 girls aged 6.1 and 5.6 y) and 3 with simple virilizing CAH (mean±SD age 5.7±2.1, bone age 12.9±1.2 y), both before and 2 to 7 months after SH suppression (SHS) with either long acting GnRHa or hydrocortisone. Serum IGF-I, LH, FSH, testosterone (T) and estradiol (E2) were measured by RIA. A GnRH test was carried out in the 3 patients with CAH. Before SHS, serum IGF-I and T (boys) or E2 (girls) were 1.52 ± 0.4 U/ml (5 to ] 11-y-old normal: 0.72±0.4) and 13.7±8.6 nmol/L or 230 pmol/L, respectively (mean±SD or mean of duplicate). After SHS, values were 1.78±0.92 and 0.93±0.14 or 10.5. IGF-I did not decrease in any patient, while SH decreased in all of them. Maximal LH and FSH responses to GnRH in CAH were 1.60±1.1 and 0.88+±.54 before SHS, and 9.27±2.25 and 6.46±2.45 U/L 2 to 12 months after SHS, respectively. Testicular enlargement and clinical evidence of central PP developed in CAH patients after SHS. It is concluded that after SHS to prepubertal values, serum IGF-I remains high in either central PP or CAH, suggesting that SH induce a maturational change in IGF-I values. Since after SHS in CAH, the GnRH test acquires a pubertal pattern of response, IGF-I might be involved in the process of maturation of the gonadostat.
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Belgorosky, A., Rivarola, M. LACK OF SUPPRESSION OF SERUM IGF-I AFTER SEX HORMONE SUPPRESSION IN TRUE AND PSEUDO PRECOCIOUS PUBERTY. Pediatr Res 33 (Suppl 5), S88 (1993). https://doi.org/10.1203/00006450-199305001-00507
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DOI: https://doi.org/10.1203/00006450-199305001-00507