Diagnostic Utility of a Low-Dose Gonadotropin-Releasing Hormone Test in the Context of Puberty Disorders

Abstract

Objectives: The 10-µg gonadotropin-releasing hormone (GnRH) test assesses pituitary gonadotroph responsiveness, whereas the 100-µg dose assesses maximal secretory capacity. Our aims were to establish normative data for the low-dose test in children and to evaluate the test in diagnosing common pubertal disorders. Methods: We retrospectively classified 107 children who underwent 10-µg GnRH tests into normal prepubertal (20 boys, 10 girls), normal early pubertal (10 boys, 16 girls), constitutional delay of puberty (CDP, 13 prepubertal boys >12 years), hypogonadotropic hypogonadism (HH, 5 prepubertal boys >12 years), central precocious puberty (CPP, 19 girls) or premature thelarche/variant (13 girls). Results: Peak LH response was higher in prepubertal boys >12 years compared with younger boys (p < 0.01) but showed no further change in early puberty. CDP boys had LH responses similar to prepubertal boys >12 years. HH boys showed an absent LH response which diagnosed HH with 100% sensitivity and 96% specificity. Thelarche girls had LH:FSH peak ratios lower than normal prepubertal (p = 0.001), pubertal (p < 0.05) or CPP (p = 0.001) girls. Conclusions: We have established normative values for the low-dose GnRH test in children. The test successfully differentiated HH from CDP in boys, and contributed to the differential diagnosis of CPP and premature thelarche in girls.

Evaluation of the Buserelin Stimulation Test in Diagnosing Gonadotropin Deficiency in Males with Delayed Puberty

“…The use of GnRH/LHRH can be enhanced with repetitive administration (priming) or prolonged infusion; [12][13][14][35][36][37] however, in contrast to the buserelin stimulation test, this approach is both cumbersome and expensive, making it impractical in the clinical setting. A recently published low-dose GnRH stimulation test (10 mg) 38 shows promise, but the study was limited by including only a small cohort of males with HH. This test also relies on a very accurate LH assay, because 1/3 of males with CDGD have peak LH values within 2 IU/L of the cutoff value for diagnosing HH.…”

Evaluation of pituitary function after traumatic brain injury in childhood

“…LH and FSH responses to stimulation were evaluated using the low‐dose GnRH test 17 . We collected blood samples for LH, FSH and oestradiol or testosterone at time 0.…”

“…A cut‐off of 450 n m was used to define an adequate peak cortisol response to glucagon 20 . We evaluated peak LH and FSH responses to the low‐dose GnRH test using locally determined reference data 17 …”

“…LH and FSH responses to stimulation were evaluated using the low-dose GnRH test. 17 We collected blood samples for LH, FSH and oestradiol or testosterone at time 0. Further samples for LH and FSH were obtained at 20 and 60 min postintravenous injection of 10 lg of GnRH.…”

Diagnosis of Diseases of Steroid Hormone Production, Metabolism and Action

“…In patients with thelarche the FSH is higher (2−7 iu/L) than the LH (1−3 iu/L), which contrasts with precocious puberty where LH secretion predominates. A GnRH stimulation test may sometimes be needed to distinguish the 2 disorders again by revealing differences in the prodominant gonadotrophin, but interpretation may be assay dependent (136, 137). Various doses of GnRH are used with 10 microgram and 100 microgram (being the most common) with blood samples at zero, 20 and 60 minutes.…”