Predictive factors for elevated prostate specific antigen and hematocrit levels during testosterone replacement therapy in patients with testosterone deficiency

Objective: We examined risk factors associated with prostate specific antigen (PSA) and hematocrit (hct) elevation during testosterone replacement therapy (TRT) in patients with testosterone deficiency (TD). Methods: We retrospectively analyzed the medical records of patients receiving TRT for >= 3 months. We investigated the following parameters: age, body mass index, comorbidities, TRT type, TRT duration, pre-TRT prostate volume, pre- and post-TRT serological tests, prostate biopsies, prostate cancer diagnoses, pre- and post-TRT aging male symptom scale scores, hct elevation, and PSA elevation. The patients were divided into two groups based on the PSA elevation status for comparison, following which we analyzed the predictive factors for PSA elevation. They were also divided into two groups based on hct elevation status. Results: The PSA elevation group showed a statistically significantly higher mean age, pre-TRT prostate volume, and PSA level compared to the non-elevation group. The PSA non-elevation group showed a significantly higher percentage of smokers, while the PSA elevation group showed a statistically significantly higher prevalence of benign prostatic hyperplasia (BPH_LUTS). The results demonstrated that a large pre-TRT prostate volume, high pre-TRT PSA levels, BPH_LUTS, and being a non-smoker were the contributing factors for PSA elevation. The hct elevation group showed statistically significantly higher pre-TRT Hb, hct, and post-TRT testosterone levels, and dyslipidemia rates, as well as a non-statistically significant prevalence of testosterone enanthate (TE) and testosterone undecanoate (TU) intramuscular injection. The pre-TRT Hb and hct levels were contributing factors for hct elevation during TRT. TE injection showed marginal statistical significance. Conclusions: We identified large prostate volumes, high PSA levels, BPH_LUTS, and being non-smokers prior to TRT as risk factors for PSA elevation during TRT. Interestingly, we found that TRT-induced hct elevation was likely to occur in patients with high pre-TRT Hb and hct levels. Additionally, the hct levels should be monitored when using TE for TRT.