(866) Prostate Specific Antigen-Based Parameters Can Predict Adult Male Hypogonadism

Introduction Male hypogonadism affects approximately 5% of men aged 40–79 years and leads to deterioration in sexual and general health. Diagnosis relies on both clinical symptoms such as low libido and erectile dysfunction, and biochemical confirmation of low testosterone levels. However, many patients are reluctant to discuss these symptoms due to embarrassment or cultural barriers, while physicians may fail to evaluate them thoroughly, resulting in underdiagnosis. Testosterone plays a crucial role in regulating multiple physiological systems, including the prostate. It modulates the transcription of the prostate-specific antigen (PSA) gene through androgen receptor activation. Consequently, serum PSA levels partly reflect androgenic activity within the prostate. Low testosterone concentrations are often associated with reduced PSA production, while higher testosterone levels may stimulate PSA expression. Because PSA testing is routinely performed in men over 50 years of age-or over 45 years with risk factors for prostate cancer-its widespread availability may offer an indirect biochemical indicator of androgen status. Objective In this study, we aimed to evaluate the relationship between PSA-based parameters and male hypogonadism to determine whether these routinely measured markers could predict testosterone deficiency and aid in identifying men who require further evaluation. Methods We conducted a retrospective analysis of patients presenting with erectile dysfunction and/or low libido to the urology outpatient clinic between July 2023 and July 2025. Clinical, endocrinological, and biochemical data were reviewed. Patients were categorized as hypogonadal (<350 ng/dL, n=68) or eugonadal (≥350 ng/dL, n=115) based on two consecutive testosterone measurements. Exclusion criteria included age <45 years, prior pelvic/scrotal surgery or radiotherapy, history of androgen deprivation or testosterone replacement therapy, history of prostatitis, and 5α-reductase inhibitor use. Results Patient characteristics are summarized in Table 1. Total PSA, free/total PSA ratio, PSA density (PSAd), and diabetes status differed significantly between groups (p=0.004, p=0.013, p=0.028, p=0.012, respectively). Regression analysis identified total PSA, free/total PSA, and PSAd as significant predictors of hypogonadism. ROC analysis demonstrated that total PSA (cutoff: 0.96 ng/mL, AUC=0.66) had 43% sensitivity and 86% specificity; PSAd (cutoff: 0.02, AUC=0.60) showed 45.1% sensitivity and 72.2% specificity; and free/total PSA (cutoff: 37.6, AUC=0.43) had 45.6% sensitivity and 69.6% specificity (Figure 1). Conclusions Total PSA, free/total PSA, and PSAd were significant predictors of male hypogonadism. These parameters may help identify men at high risk for hypogonadism, prompting more thorough evaluation of related symptoms. Incorporating PSA-based parameters could reduce underdiagnosis and improve patient counseling and management. Disclosure No