Journal of Andrology
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH
Published-Ahead-of-Print February 10, 2006, DOI:10.2164/jandrol.05140

This Article
Right arrow Author Manuscript (PDF)
Right arrow All Versions of this Article:
27/3/358    most recent
Author Manuscript (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Shimon, I.
Right arrow Articles by Ilany, J.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Shimon, I.
Right arrow Articles by Ilany, J.

FEEDBACK INHIBITION OF GONADTROPINS BY TESTOSTERONE IN MEN WITH HYPOGONADOTROPIC HYPOGONADISM: COMPARISON TO THE INTACT PITUITARY-TESTICULAR AXIS IN PRIMARY HYPOGONADISM

Ilan Shimon , Alexandra Lubina , Malka Gorfine , and Jacob Ilany

Men with hypogonadotropic hypogonadism (HH) due to hypothalamic-pituitary disease present with low serum testosterone levels combined with undetectable, low, or normal gonadotropin levels. Treatment consists of testosterone replacement to reverse the symptoms of androgen deficiency. The aim of this study was to examine the dynamics and feedback inhibition of follicle-stimulating hormone (FSH) and luteinizing hormone (LH) in relation to testosterone in 38 men with HH treated with testosterone. Findings were compared with 11 men with primary hypergonadism (PH). Testosterone replacement led to a suppression of FSH levels from 2.8 IU/L at baseline to 1.1 IU/L, and in LH levels, from 2.3 to 0.8 IU/L. There was a linear correlation between levels of FSH and LH (both after Ln transformation) and testosterone levels in both the HH and PH groups. However, the differences in intercepts and slopes between the groups were significant. To determine whether non-suppressed FSH or LH during testosterone replacement reduces the probability of eugonadism, as reflected by normal testosterone levels, gonadotropins were categorized according to low (<0.5 IU/L), medium (0.5 - 2 IU/L), and high levels (>2 IU/L). The higher FSH or LH levels were found to significantly decrease the chance for achieving eugonadism.

In conclusion, in men with HH due to hypothalamic-pituitary disease or injury, the pituitary-testicular hormonal axis maintains its physiological negative feedback between testosterone and gonadotropins. Thus, gonadotropin levels in men with HH might be useful, together with testosterone concentrations, for assessing the adequacy of androgen replacement.




This article has been cited by other articles:


Home page
 J AndrolHome page
B. Kornmann, E. Nieschlag, M. Zitzmann, J. Gromoll, M. Simoni, and S. Von Eckardstein
Body Fat Content and Testosterone Pharmacokinetics Determine Gonadotropin Suppression After Intramuscular Injections of Testosterone Preparations in Normal Men
J Androl, September 1, 2009; 30(5): 602 - 613.
[Abstract] [Full Text] [PDF]


HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH
Copyright © 2006 by The American Society of Andrology.