Testosterone products are required by the U.S. Food and Drug Administration (FDA) to come with a warning stating that testosterone replacement therapy (TRT) used by men with benign prostate hyperplasia (BPH) may increase the risk of worsening the progression of the disease.
Recent studies now reveal no increased risk of using TRT with BPH or with lower urinary tract symptoms (LUTS) and BPH (LUTS/BPH). Some studies even suggest that TRT can improve LUTS.
The opinion from researchers of the most recent study, “Testosterone Replacement Therapy and LUTS/BPH. What is the Evidence?” published in Current Urology Reports, concluded: “TRT is not a risk factor for LUTS/BPH and the warning set forth by the FDA likely needs reevaluation.”
In the 1940s, a pilot study showed that castration helped thwart prostate cancer progression, whereas giving testosterone resulted in prostate growth – which led to the belief that prostatic growth could be proportional to testosterone levels. But the assumptions were made on thin data: with just one patient, and examined prostate cancer tissue rather than normal prostatic tissue.
More recent data shows that prostate volume increases over time, regardless of testosterone levels. Younger men have much higher levels of naturally available testosterone than older men, but they do not have increased rates of prostate cancer growth.
Several studies also demonstrated that an increase in prostate size does not correlate with worsening of LUTS/BPH symptoms.
Physiologically, testosterone seems beneficial for preventing LUTS/BPH. The disorders are thought to be caused by three major contributors: pelvic atherosclerosis; increased muscle tone; and nitric oxide deficiency, which causes restriction of blood supply in the pelvis and chronic hypoxia (oxygen deficiency) in the prostate and bladder.
In other findings, testosterone was shown to reduce hypoxia through the modulation of nitric oxide production in a similar mechanism as phosphodiesterase-5 inhibitors, suggesting that it may have a role in reducing LUTS/BPH.
Overall, the research revealed that testosterone is not a risk factor for worse LUTS/BPH symptoms and that the mandatory warning featured on testosterone products should be re-evaluated by the FDA.