Gonadotropin releasing hormone agonist (nafarelin) test to differentiate gonadotropin deficiency from constitutionally delayed puberty in teen-age boys--a clinical research center study.

The objective of this study was to determine whether the hormonal response to a GnRH agonist (nafarelin) challenge differentiates hypogonadotropinism from delayed puberty as well as the sleep test does. We studied boys ages 13.25-17.6 yr with prepubertal constitutional delay of puberty (CDP, n = 11), prepubertal gonadotropin deficiency (GnD, n = 10), pubertal CDP (PCDP, n = 11) and partial GnD (PGnD, n = 2). These disorders were defined on the basis of the following independent criteria: CDP = isolated delayed puberty with documentation of subsequent pubertal progression; GnD = panhypopituitarism or anosmia with absence of subsequent pubertal progression; PCDP = isolated delayed puberty in an early pubertal child; and PGnD = arrest of puberty in boys with partial hypopituitarism. CDP was compared with GnD and PCDP was compared with PGnD by analysis of variance and two-tailed t tests. Each patient had a nafarelin test with measurement of LH, FSH, and testosterone responses at intervals after nafarelin admi...