Gonadorelin

Six men with idiopathic hypogonadotropic hypogonadism received low-dose GnRH delivered subcutaneously in episodic (pulsatile) pulses via a portable infusion pump, mimicking physiologic hypothalamic secretion. Serum gonadotropins normalized within one week and rose above normal by two weeks, and testosterone increased from a markedly suppressed baseline (77 +/- 13 ng/dL) into the adult range. Four patients showed testicular growth and three achieved spermatogenesis by 43 weeks, demonstrating that pulsatile, rather than continuous, GnRH delivery reverses the pituitary-gonadal defect.

In men whose bodies never triggered puberty because the brain fails to release the hormone that starts it, doctors used a small pump to deliver GnRH in tiny timed bursts like the body normally would. Within weeks the men's hormone levels became normal and testosterone climbed to adult levels. Several developed larger testes and began producing sperm, showing this pump approach can jump-start delayed puberty and fertility.

Fifteen girls and seventeen boys with delayed or arrested puberty were treated with subcutaneous pulsatile GnRH at 90-minute intervals (1-2 micrograms/pulse for girls, 2-4 micrograms/pulse for boys). Clinical features, growth acceleration, endocrine profiles, and ovarian ultrasound morphology reproduced those of normal spontaneous puberty. Measurement of spontaneous gonadotropin pulsatility after treatment withdrawal distinguished 20 patients with hypogonadotropic hypogonadism from 12 with constitutional delay of growth and puberty, confirming that normal puberty is GnRH-dependent.

Children with delayed puberty were given GnRH through a pump that released a small dose every 90 minutes, matching the body's natural rhythm. Their growth, hormone changes, and physical development matched what normally happens in puberty. Stopping the treatment and rechecking hormone patterns also helped doctors tell apart kids who were simply late bloomers from those with a permanent hormone deficiency.

Investigators compared GnRH (gonadorelin) stimulation test responses across 91 patients with idiopathic hypogonadotropic hypogonadism, 27 with constitutional delay of growth and puberty, 6 prepubertal children, and 20 pubertal adults to derive diagnostic cut-offs. In males, a serum basal LH <0.6 IU/L or peak LH <9.74 IU/L yielded moderate sensitivity (73.8%/80.0%) and specificity (90.9%/86.4%); in females, basal LH <0.85 IU/L or basal FSH <2.43 IU/L gave sensitivities of 80.0%/100.0% and specificities of 75.0%/50.0%. The authors concluded the test alone adequately differentiates hypogonadotropic hypogonadism from constitutional delay in males, with basal or peak LH being the most useful predictor.

Doctors gave a GnRH injection and measured how much the pituitary gland released the hormones LH and FSH, then compared results between patients with a true hormone deficiency and those who were just late to enter puberty. They identified LH threshold levels that reliably separated the two groups, especially in boys. This helps clinicians decide whether a teenager with delayed puberty needs treatment or will develop normally on their own.