Abstract
Androgen replacement therapy (ART) is a widely accepted form of treatment worldwide for aging men with late-onset hypogonadism (LOH) syndrome. Concurrent with the progressive decline in testosterone from middle age, there is a gradual increase in prostate volume, reflecting the development of benign prostatic hyperplasia (BPH). Prostate growth is dependent on the presence of androgens, and conversely, antiandrogen agents or orchidectomy can decrease prostate volume in patients with BPH. Thus, it is important to investigate whether ART could have any negative effects on prostatic disease or lower urinary tract symptoms (LUTS). Although only limited amounts of information on the correlations between androgen levels in aging men and clinical manifestations of LUTS are available, a few recent studies have suggested that testosterone levels may have some beneficial effects on various urinary functions in men. Androgen receptors are found in the urothelium, urinary bladder, prostate, and urethra, and testosterone could have an impact on the autonomic nervous system, bladder smooth muscle differentiation, nitric oxide synthase, phosphodiesterase-5 and Rho/Rho-kinase activities, and pelvic blood flow. In addition, some previous studies demonstrated that ART had little effect on LUTS or urinary function in aging men with LOH syndrome. Furthermore, some recent randomized controlled trials indicated that short-term ART may be effective in the improvement of LUTS in hypogonadal men with mild BPH. However, only limited information is available regarding the effects of longer-term ART or the safety of ART in men with severe BPH and LUTS, and further studies are required to reach more definitive conclusions.