Tf. Kolon et Of. Miller, Comparison of single versus multiple dose regimens for the human chorionicgonadotropin stimulatory test, J UROL, 166(4), 2001, pp. 1451-1454
Purpose: Human chorionic gonadotropin (HCG) has a stimulatory effect on tes
ticular steroidogenesis and has been widely used for evaluating male Leydig
cell function. However, considerable variability exists in the protocols f
or HCG stimulation tests. In the most commonly used protocols HCG is admini
stered daily for several days. We examine the circulating androgen response
after I and 3-dose HCG regimens.
Materials and Methods: We evaluated 77 prepubertal boys diagnosed with hypo
spadias, cryptorchidisin or micropenis. In 60 boys who underwent 1 dose of
100 IU/kg. or 5,000 IU/1.7 m.(2) HCG serum testosterone and dihydrotestoste
rone were sampled at 72 (28) and 96 (32) hours after injection, while in 17
who underwent 3 daily age adjusted doses hormone levels were determined on
day 4. All blood specimens were obtained and injections were performed at
8:00 to 9:00 a.m. and all specimens were evaluated at the same endocrine re
ference laboratory.
Results: Nonstimulated testosterone levels were prepubertal in all groups.
In the 1-dose groups post-stimulation testosterone was elevated 22 to 29-fo
ld from baseline after a weight based and 34 to 35-fold after a body surfac
e area based dose. Testosterone increased 20-fold baseline in the multi-dos
e group. No significant differences were observed in 72 versus 96-hour horm
one levels.
Conclusions: Evaluating Leydig cell function by HCG stimulation is an impor
tant adjunct to the diagnosis of various urological conditions. A single we
ight or body surface area based HCG dose with androgen measurement after 3
or 4 days is a practical, reliable and cost saving change in testicular eva
luation.