Leuteinizing hormone responses to leuprolide acetate discriminate between hypogonadotropic hypogonadism and constitutional delay of puberty.

OBJECTIVE: To assess if leuprolide acetate stimulation discriminates between hypogonadotropic hypogonadism (HH) and constitutional delay of puberty (CDP) in males.

DESIGN: Case-control study.

SETTING: Patients attending an academic research environment.

PATIENTS: Only male patients were studied: 10 with HH (group 1, age 16.5 +/- 6.0 years), 8 prepubertal with CDP (group 2, age 14.3 +/- 1.2 years), 6 healthy prepubertal (group 3, age 9.5 +/- 3.3 years), and 8 healthy late-pubertal (group 4, age 15.1 +/- 3.1 years).

INTERVENTION(S): Blood samples were obtained after an overnight fast. Leuprolide acetate was then administered SC, and blood samples were drawn at 0, 30, 60, 120, 180 minutes, and 6 and 24 hours after stimulation.

MAIN OUTCOME MEASURE(S): Clinical follow-up evaluations of data and serum levels of LH, FSH, 17-hydroxyprogesterone, and testosterone.

RESULT(S): Basal LH levels were similar in groups 1 through 3 and differed significantly from those in group 4. Peak serum LH levels were significantly higher in CDP compared with HH (8.9 +/- 1.4 vs. 1.4 +/- 0.2 IU/L). Baseline FSH levels were significantly higher only in pubertal boys (versus the HH group); peak levels did not differ among the groups. Basal and peak testosterone levels were significantly higher only in the control pubertal group when compared to the other groups; peak 17-hydroxyprogesterone concentrations were significantly higher in pubertal controls compared with HH and CDP.

CONCLUSION(S): Peak LH responses clearly discriminate HH from CDP. Timing for blood sampling should be fixed at 0, 60, 120, 180 minutes after stimulation.