Serum PSA as a Predictor of Testosterone Deficiency

Authors

  • Giulia Rastrelli MD,

    1. Sexual Medicine and Andrology Unit, Department of Biomedical, Experimental, and Clinical Sciences, University of Florence, Florence, Italy
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  • Giovanni Corona PhD,

    1. Sexual Medicine and Andrology Unit, Department of Biomedical, Experimental, and Clinical Sciences, University of Florence, Florence, Italy
    2. Endocrinology Unit, Maggiore-Bellaria Hospital, Bologna, Italy
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  • Linda Vignozzi PhD,

    1. Sexual Medicine and Andrology Unit, Department of Biomedical, Experimental, and Clinical Sciences, University of Florence, Florence, Italy
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  • Elisa Maseroli MD,

    1. Sexual Medicine and Andrology Unit, Department of Biomedical, Experimental, and Clinical Sciences, University of Florence, Florence, Italy
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  • Antonio Silverii MD,

    1. Sexual Medicine and Andrology Unit, Department of Biomedical, Experimental, and Clinical Sciences, University of Florence, Florence, Italy
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  • Matteo Monami PhD,

    1. Diabetes Section, Geriatric Unit, Department of Critical Care, University of Florence, Florence, Italy
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  • Edoardo Mannucci MD,

    1. Diabetes Section, Geriatric Unit, Department of Critical Care, University of Florence, Florence, Italy
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  • Gianni Forti MD,

    1. Sexual Medicine and Andrology Unit, Department of Biomedical, Experimental, and Clinical Sciences, University of Florence, Florence, Italy
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  • Mario Maggi MD

    Corresponding author
    • Sexual Medicine and Andrology Unit, Department of Biomedical, Experimental, and Clinical Sciences, University of Florence, Florence, Italy
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Corresponding Author: Mario Maggi, MD, Sexual Medicine and Andrology Unit, Department of Biomedical, Experimental, and Clinical Sciences, University of Florence, Viale Pieraccini 6, 50139 Florence, Italy. Tel: +39-55-4271415; Fax: +39-55-4271413; E-mail: m.maggi@dfc.unifi.it

Abstract

Introduction

The relationship between serum prostate-specific antigen (PSA) and testosterone (T) levels is still controversial. According to the “saturation hypothesis,” a significant relationship is apparent only in the low T range.

Aim

To verify whether, in a large sample of male subjects seeking medical care for sexual dysfunction (SD), PSA might represent a reliable marker of T levels.

Methods

A consecutive series of 3,156 patients attending our unit for SD was studied. Among them, only subjects without history of prostate disease and with PSA levels <4 ng/mL (N = 2,967) were analyzed.

Main Outcome Measures

Several hormonal and biochemical parameters were studied, along with structured interview on erectile dysfunction (SIEDY), ANDROTEST, and PsychoANDROTEST.

Results

Receiver operating characteristic curve analysis for predicting severe hypogonadism (T < 8 nmol/L) showed an accuracy of PSA = 0.612 ± 0.022 (P < 0.0001), with the best sensitivity and specificity at PSA < 0.65 ng/mL (65.2% and 55.5%, respectively). In the entire cohort, 254 subjects (8.6%) showed T < 8 nmol/L and, among them, more than half (N = 141, 4.8%) had PSA < 0.65 ng/mL. After adjusting for age, low PSA was associated with hypogonadism-related features (i.e., delayed puberty, lower testis volume) and associated conditions, such as metabolic syndrome (hazard ratio [HR] = 1.506 [1.241–1.827]; P < 0.0001), type 2 diabetes (HR = 2.044 [1.675–2.494]; P < 0.0001), and cardiovascular diseases (HR = 1.275 [1.006–1.617]; P = 0.045). Furthermore, low PSA was associated with impaired sex- and sleep-related erections. The association between low PSA and hypogonadal symptoms and signs as well as with metabolic syndrome was retained even after adjusting for T levels. Sensitivity and positive predictive values of low PSA increased, whereas specificity and negative predictive value decreased as a function of age.

Conclusions

PSA is a marker of T concentrations and it may represent a new tool in confirming hypogonadism. The determination of PSA levels might give insights not only on the circulating levels of total T but also on its active fractions. Rastrelli G, Corona G, Vignozzi L, Maseroli E, Silverii A, Monami M, Mannucci E, Forti G, and Maggi M. Serum PSA as a predictor of testosterone deficiency. J Sex Med 2013;10:2518–2528.

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