[Prognostic values of the determination of sleep-related gonadotropin rhythm in delayed puberty].

Sleep-related gonadotropin rhythms are specific for puberty. Sleep-dependent increases of prolactin, follicle-stimulating hormone (FSH) and luteinizing hormone (LH) were studied in 6 boys and 1 girl with constitutional delay of growth and puberty. The purpose of this study was to determine whether gonadotropin rhythms occur in the same hormonal sequence in children with constitutional delay of puberty as in normal children. At the onset of puberty a sleep-related FSH increase was detectable, followed by LH-rhythms 1 to 2 years later. The findings of a sleep-dependent FSH increase excludes a hypogonadotropic hypogonadism and triggers the development of secondary sex characteristics.