Free Androgen Index Is Superior to Total Testosterone for Short-Term Assessment of the Gonadal Axis after Renal Transplantation

• Published in: Hormone research Vol. 64; no. 5; pp. 248 - 252
• Main Authors: Reinhardt, Walter, Patschan, Daniel, Pietruck, Frank, Philipp, Thomas, Janssen, Onno E., Mann, Klaus, Jockenhövel, Friedrich, Witzke, Oliver
• Format: Journal Article
• Language: English
• Published: Basel, Switzerland S. Karger AG 01.01.2005
• Subjects: Adult; Androgens - blood; Humans; Kidney Transplantation - physiology; Male; Middle Aged; Original Paper; Pituitary Gland - physiology; Sex Hormone-Binding Globulin - analysis; Testis - physiology; Testosterone - blood; Time Factors; Renal transplantation; Testosterone; Pituitary-gonadal axis; Hypogonadism
• ISSN: 1663-2818; 0301-0163; 1663-2826
• DOI: 10.1159/000089292

Objective: Recent studies have assessed gonadal function in association with different immunosuppressive drugs in transplanted patients mainly relying on the measurement of total testosterone. It is the aim of this study to assess the short-term changes of the hypothalamic-pituitary-gonadal axis following renal transplantation using the free androgen index (FAI). Patients and Methods: The sequential changes in total testosterone, sex hormone-binding globulin (SHBG), gonadotropin and prolactin concentrations were measured in 22 male patients before and after 1–3 days, and 1, 2 and 3 weeks following renal transplantation. Results: Total testosterone and SHBG concentrations dropped significantly after transplantation (total testosterone: baseline: 15.2 ± 1.6 nmol/l vs. 1 week: 7.9 ± 0.8 nmol/l vs. 2 weeks: 9.8 ± 0.9 nmol/l, SHBG: baseline: 29.9 ± 3.2 nmol/l vs. 1 week: 19.9 ± 2.1 nmol/l, 2 weeks: 18.9 ± 2.4 nmol/l, p < 0.01). FAI decreased significantly after day 1–3 returning to values near baseline thereafter (baseline: 60 ± 9% vs. day 1–3: 38 ± 6%, 2 weeks: 61 ± 7%; p < 0.01). There was a significant positive correlation between FAI and renal function. Conclusion: Measurement of the free androgen index is superior to total testosterone for assessment of the pituitary-gonadal axis in the first weeks after renal transplantation.