Basal Follicle-Stimulating Hormone and Peak Gonadotropin Levels after Gonadotropin-Releasing Hormone Infusion Show High Diagnostic Accuracy in Boys with Suspicion of Hypogonadotropic Hypogonadism

GRINSPON R; ROPELATO MG; GOTTLIEB S; KESELMAN A; MARTINEZ A; BALLERINI MG; DOMENÉ HM; REY RA

JOURNAL OF CLINICAL ENDOCRINOLOGY AND METABOLISM

ENDOCRINE SOC

Año: 2009

0021-972X

Context: Differential diagnosis between hypogonadotropic hypogonadism (HH) and constitutional delay of puberty in boys is challenging. Most tests use an acute GnRH stimulus, allowing only the release of previously synthesized gonadotropins. A constant GnRH infusion, inducing de novo delay of puberty in boys is challenging. Most tests use an acute GnRH stimulus, allowing only the release of previously synthesized gonadotropins. A constant GnRH infusion, inducing de novo gonadotropin synthesis, may allow a better discrimination. Objective: We evaluated the diagnostic accuracy of basal and peak gonadotropins after GnRH infusion, measured by ultrasensitive assays, to confirm the diagnosis in boys with suspected HH. infusion, measured by ultrasensitive assays, to confirm the diagnosis in boys with suspected HH. Design and Setting: We conducted a validation study following Standards for Reporting of Diagnostic Accuracy criteria at a tertiary public hospital. Design and Setting: We conducted a validation study following Standards for Reporting of Diagnostic Accuracy criteria at a tertiary public hospital. Patients and Methods: A GnRH iv infusion test was performed in 32 boys. LH and FSH were determined by immunofluorometric assay at 0–120 min. determined by immunofluorometric assay at 0–120 min. Diagnosis Ascertainment: The following diagnoses were ascertained: complete HH (n
19; testes 4 ml at 18 yr), partial HH (n
6; testes enlargement remained arrested for
1 yr or did not reach 15 ml), and constitutional delay of puberty (n
7; testes
15 ml at 18 yr). 15 ml), and constitutional delay of puberty (n
7; testes
15 ml at 18 yr). Main Outcome Measures: Sensitivity, specificity, positive and negative predictive values, and diagnostic efficiency were assessed. Results: Basal FSH less than 1.2 IU/liter confirmed HH with specificity of 1.00 (95% confidence interval
0.59–1.00), rendering GnRH infusion unnecessary. In patients with basal FSH of at least 1.2 IU/liter, the coexistence of peak FSH less than 4.6 IU/liter and peak LH less than 5.8 IU/liter after GnRH infusion had high specificity (1.00; 95% confidence interval
0.59–1.00) and diagnostic efficiency (76.9%) for HH. efficiency (76.9%) for HH. 1.2 IU/liter, the coexistence of peak FSH less than 4.6 IU/liter and peak LH less than 5.8 IU/liter after GnRH infusion had high specificity (1.00; 95% confidence interval
0.59–1.00) and diagnostic efficiency (76.9%) for HH. efficiency (76.9%) for HH. 4 ml at 18 yr), partial HH (n
6; testes enlargement remained arrested for
1 yr or did not reach 15 ml), and constitutional delay of puberty (n
7; testes
15 ml at 18 yr). 15 ml), and constitutional delay of puberty (n
7; testes
15 ml at 18 yr). Main Outcome Measures: Sensitivity, specificity, positive and negative predictive values, and diagnostic efficiency were assessed. Results: Basal FSH less than 1.2 IU/liter confirmed HH with specificity of 1.00 (95% confidence interval
0.59–1.00), rendering GnRH infusion unnecessary. In patients with basal FSH of at least 1.2 IU/liter, the coexistence of peak FSH less than 4.6 IU/liter and peak LH less than 5.8 IU/liter after GnRH infusion had high specificity (1.00; 95% confidence interval
0.59–1.00) and diagnostic efficiency (76.9%) for HH. efficiency (76.9%) for HH. 1.2 IU/liter, the coexistence of peak FSH less than 4.6 IU/liter and peak LH less than 5.8 IU/liter after GnRH infusion had high specificity (1.00; 95% confidence interval
0.59–1.00) and diagnostic efficiency (76.9%) for HH. efficiency (76.9%) for HH. Main Outcome Measures: Sensitivity, specificity, positive and negative predictive values, and diagnostic efficiency were assessed. Results: Basal FSH less than 1.2 IU/liter confirmed HH with specificity of 1.00 (95% confidence interval
0.59–1.00), rendering GnRH infusion unnecessary. In patients with basal FSH of at least 1.2 IU/liter, the coexistence of peak FSH less than 4.6 IU/liter and peak LH less than 5.8 IU/liter after GnRH infusion had high specificity (1.00; 95% confidence interval
0.59–1.00) and diagnostic efficiency (76.9%) for HH. efficiency (76.9%) for HH. 1.2 IU/liter, the coexistence of peak FSH less than 4.6 IU/liter and peak LH less than 5.8 IU/liter after GnRH infusion had high specificity (1.00; 95% confidence interval
0.59–1.00) and diagnostic efficiency (76.9%) for HH. efficiency (76.9%) for HH. Results: Basal FSH less than 1.2 IU/liter confirmed HH with specificity of 1.00 (95% confidence interval
0.59–1.00), rendering GnRH infusion unnecessary. In patients with basal FSH of at least 1.2 IU/liter, the coexistence of peak FSH less than 4.6 IU/liter and peak LH less than 5.8 IU/liter after GnRH infusion had high specificity (1.00; 95% confidence interval
0.59–1.00) and diagnostic efficiency (76.9%) for HH. efficiency (76.9%) for HH. 1.2 IU/liter, the coexistence of peak FSH less than 4.6 IU/liter and peak LH less than 5.8 IU/liter after GnRH infusion had high specificity (1.00; 95% confidence interval
0.59–1.00) and diagnostic efficiency (76.9%) for HH. efficiency (76.9%) for HH. Conclusions: Basal FSH less than 1.2 IU/liter confirms HH, which precludes from further testing, reducing patient discomfort and healthcare system costs. In patients with basal FSH of at least 1.2 IU/liter, a GnRH infusion test has a high diagnostic efficiency. reducing patient discomfort and healthcare system costs. In patients with basal FSH of at least 1.2 IU/liter, a GnRH infusion test has a high diagnostic efficiency.