The effects of kidney transplantation on sex hormones, sperm parameters, and fertility rate in males: A systematic review.

Background: End-stage renal disease (ESRD) is reported to be associated with the impairment of sex hormones, including decreased testosterone levels and increased follicle-stimulating hormone (FSH), luteinizing hormone (LH), and prolactin levels. Additionally, patients with ESRD often experience impaired spermatogenesis, leading to infertility. However, variations in study methodologies and reported outcomes make it challenging to draw definitive conclusions. Therefore, this study aims to evaluate the effects of kidney transplantation (KT) on these issues, which can be useful in counseling male patients with ESRD.

Methods: A systematic search was conducted in Web of Science, Medline (via PubMed), and Embase (via Scopus) to identify peer-reviewed studies evaluating the impact of KT on sex hormones and reproductive parameters. A systematic review (SR) was conducted following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. This review included English-language articles published between January 1975 and December 2024. Excluded from this search were reviews, editorials, book chapters, conference abstracts, case reports, and case series with up to four patients were excluded.

Results: A total of 2939 publications were initially identified, and 23 studies met the inclusion criteria, comprising 738 patients for analysis. Most studies reported a significant increase in testosterone levels 3, 6, and 12 months post-KT. LH and prolactin levels exhibited a trend parallel to that of testosterone. A statistically significant decrease in LH levels was observed at both 1 and 12 months post-KT, while prolactin levels showed a significant reduction at all evaluated time points from 1 to 12 months. In contrast, FSH levels fluctuated over time and did not demonstrate statistical significance at any assessment point. Additionally, KT led to improvements in testis biopsy findings, and all categories of sperm parameters.

Conclusion: This SR demonstrates that KT improves sex hormone levels, sperm parameters, and sexual function in male kidney recipients. However, to gain a more comprehensive understanding of the sexual health of male kidney recipients, the establishment of an international database with prospectively collected data is warranted.