What is known about testosterone, sexual and urinary function
The 2010 Endocrine Society Clinical Practice Guideline cautioned against the use of testosterone replacement therapy in patients with severe LUTS.6 However, it has been pointed out that LUTS is in part due to reduced testosterone levels.7 Support for this comes from six recent randomized controlled trials which all showed that testosterone therapy in patients with LUTS does not worsen LUTS symptoms - measured by the validated International Prostate Symptom Score (IPSS) questionnaire - compared to placebo.8-13 Even in men with severe LUTS, no differences in IPSS were seen in men receiving testosterone replacement therapy vs. placebo.13 Notably, there was actually a small improvement in IPSS scores in the testosterone treated group.13
A meta-analysis of 14 clinical trials investigating the effect of testosterone therapy on LUTS reported that the change in IPSS was similar among men receiving testosterone therapy versus placebo, suggesting that testosterone treatment does not worsen LUTS.14
A systematic review of 35 trials evaluating the effects of testosterone therapy on LUTS and prostate volume found that in the majority of trials there was no significant prostate growth due to testosterone therapy.15 Studies of men with baseline mild LUTS demonstrated either no change or an improvement in symptoms after treatment. There was a lack of relevant urodynamic studies. Trials of men with the metabolic syndrome demonstrated uniform improvement in lower urinary tract symptoms. It was concluded that there is minimal support for a causative link between testosterone therapy, de novo LUTS or worsening of existing LUTS or prostate volume.15 Notably, this systemic review found an absence of high quality evidence that would support guideline recommendations that testosterone therapy is relatively contraindicated in men with severe LUTS.15 Future clinical trials with more inclusive voiding criteria are needed.
What this study adds
The study in the Journal of Urology was an observational, prospective, cumulative registry study in 656 men with a mean age of 61 years who had total testosterone levels of 12.1 nmol/L or less, and symptoms of hypogonadism.5 The testosterone treated group, comprising 360 men, received parenteral testosterone undecanoate 1,000 mg/12 weeks for up to 10 years. The 296 men who elected against testosterone therapy served as controls. From each group 82 patients were propensity matched for age, waist circumference and body mass index, resulting in 82 matched pairs of 164 men.
Results showed that testosterone therapy significantly decreased IPSS and post-void bladder volume. There were also significant improvements in the Aging Males' Symptoms Scale and the IIEF-EF (International Index of Erectile Function-Erectile Function) domain. In untreated hypogonadal men voiding and erectile function deteriorated with continued follow-up. Notably, the significant improvements in LUTS were assessed both subjectively by IPSS and objectively by reductions in ultrasound-measured post-void bladder volume.
The effect of testosterone on these outcomes is described in more detail below.
Lower urinary tract symptoms
As shown in figure 1, testosterone treated men had a marked, progressive, sustained and significant reduction in IPSS. The decrease in IPSS was largest during the first 2 years. In contrast, in the untreated group IPSS gradually increased. Even after adjustment for baseline age, weight, waist circumference, fasting blood glucose, blood pressure, lipids and AMS score there were significant differences in IPSS throughout the follow-up period.