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ORIGINAL RESEARCH article

Front. Endocrinol.
Sec. Pituitary Endocrinology
Volume 15 - 2024 | doi: 10.3389/fendo.2024.1496906

Prevalence and Predictive Factors of Testosterone-induced Erythrocytosis: A Retrospective Single Center Study

Provisionally accepted
Anina Neidhart Anina Neidhart 1Viktor von Wyl Viktor von Wyl 2,3Benno Käslin Benno Käslin 4Christoph Henzen Christoph Henzen 1Stefan Fischli Stefan Fischli 1*
  • 1 Division of Endocrinology, Diabetes and Clinical Nutrition, Luzerner Kantonsspital, Luzern, Switzerland
  • 2 Institute for Implementation Science in Health Care, Faculty of Medicine, University of Zurich, Zürich, Zürich, Switzerland
  • 3 Department of Epidemiology, Institute of Epidemiology, Biostatistics and Prevention, Faculty of Medicine, University of Zurich, Zurich, Zurich, Switzerland
  • 4 Department of Control and Operations, Faculty of Aerospace Engineering, Delft University of Technology, Delft, Netherlands

The final, formatted version of the article will be published soon.

    Aim This study analyzes the prevalence and predictive factors of testosterone-induced erythrocytosis (TIE) in patients receiving testosterone replacement therapy (TRT). Methods Retrospective single-center observational study. Results 247 patients were included; median age was 47.0 years (interquartile range (IQR) 32-60) and median follow-up years 2.9 (1.0-5.5). The most common indication for TRT was central hypogonadism (51%) followed by primary hypogonadism (26%). TRT was carried out with testosterone undecanoate (TU) n=194, testosterone enanthate (TE) n=18 and testosterone gel (n=35). Compared to baseline, hematocrit (HCT) values at last follow-up (LFU) increased significantly by +0.04 (95% confidence interval (CI) [0.027, 0.050], p=<0.0001) in all patients (n=92) and +0.06 (95%CI [0.031, 0.057], p<0.0001) in the TU group (n=71). 57% of the patients reached an HCT value>0.46, 23% >0.5 and 5%>0.54. 46% of the patients who have reached an HCT value >0.46 have had their highest HCT measurement within the first year of TRT application. Logistic regression analysis indicated that body mass index (BMI) was significantly associated with the development of an HCT ≥0.5 (p=0.013) and HCT ≥0.46 (p=0.008). There was an association between the baseline HCT measurement and the outcome of a HCT measurement ≥0.46 (p=0.025), patients with high starting values were more likely to develop TIE. Conclusions TIE appears to be frequent and does not only present within the first year of therapy which indicates a close follow-up of laboratory values within the first year followed by annual controls. Baseline BMI and baseline HCT measurement should be considered in risk stratification of TIE development.

    Keywords: Hypogonadism, testosterone replacement therapy, Erythrocytosis, Predictive factors, Risk factors

    Received: 15 Sep 2024; Accepted: 26 Dec 2024.

    Copyright: © 2024 Neidhart, von Wyl, Käslin, Henzen and Fischli. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.

    * Correspondence: Stefan Fischli, Division of Endocrinology, Diabetes and Clinical Nutrition, Luzerner Kantonsspital, Luzern, Switzerland

    Disclaimer: All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article or claim that may be made by its manufacturer is not guaranteed or endorsed by the publisher.