Dynamic GnRH and hCG testing: establishment of new diagnostic reference levels

Abstract

We provide novel reference ranges for GnRH and hCG test in healthy men, which allows future diagnostic evaluation of hypothalamic-pituitary-gonadal disorders in men.

Human Chorionic Gonadotropin Test: Old Uncertainties, New Perspectives, and Value in 46,XY Disorders of Sex Development

“…During puberty, as the basal concentrations are higher, the expected testosterone increase over the baseline is lower than in prepubertal boys [Savage, 1992;Kauschansky et al, 1995], even if the absolute Δ-increment (in ng/mL) may be higher than during prepuberty [Kauschansky et al, 1995], but opposing data have been shown in early puberty [Forest, 1979]. In healthy men, testosterone levels before and after uhCG stimulation (5,000 IU in a single dose) evaluated by mass spectrometry ( n = 72; age 18-40 years) showed a median increase of 111% (2.5-97.5 percentile: 35-347%) ( Table 2 ) [Bang et al, 2017]. In this study, none of the tested LH-GC receptor polymorphisms modulated the hCG response; a significant association between FSH-related SNPs and the testosterone increase was found, but the differences were small, leading to the conclusion that none of the examined polymorphisms had a major impact on the test results [Bang et al, 2017].…”

“…In healthy men, testosterone levels before and after uhCG stimulation (5,000 IU in a single dose) evaluated by mass spectrometry ( n = 72; age 18-40 years) showed a median increase of 111% (2.5-97.5 percentile: 35-347%) ( Table 2 ) [Bang et al, 2017]. In this study, none of the tested LH-GC receptor polymorphisms modulated the hCG response; a significant association between FSH-related SNPs and the testosterone increase was found, but the differences were small, leading to the conclusion that none of the examined polymorphisms had a major impact on the test results [Bang et al, 2017].…”

“…This may be due to inadequate grouping according to age and/or stage of pubertal development, batch-to-batch variation in uhCG used for testing (see below), use of different testing protocols, genetic polymorphisms in gonadotropin receptors, etc. Differences in testosterone assays may contribute, too [Bertelloni et al, 2010;Bang et al, 2017].…”

Hypothalamic Response to Kisspeptin-54 and Pituitary Response to Gonadotropin-Releasing Hormone Are Preserved in Healthy Older Men

“…The discrepancy between the LH and FSH responses to kisspeptin-54 and GnRH could partly be ascribed to differences in baseline serum gonadotropin levels. The absolute rise in serum LH following GnRH correlates strongly with the rise in serum FSH, whilst higher baseline gonadotropin levels often result in exaggerated responses to GnRH [19]. Although non-significant, there was a trend towards higher baseline FSH levels in older men (3.7 vs. 2.5 IU/L), whereas baseline LH levels (3.7 vs. 3.5 IU/L) were more similar between the groups, perhaps reflecting a difference in inhibin.…”

“…Currently, only pituitary function can be direct ly evaluated using gonadotropin-releasing hormone (GnRH) [19]. Gonadotropin response to GnRH is similar in older and younger men, suggesting that the pituitary remains responsive to GnRH [15-18].…”