Abstract and Introduction
Abstract
Recent large-scale epidemiological studies have documented a strong association between lower urinary tract symptoms (LUTS) and erectile dysfunction (ED). This observation has two important scientific and clinical aspects: (i) to reveal the pathomechanism linking LUTS and ED and (ii) to consider this fact in the individual approach for diagnosis and management of these two disorders. The following hypotheses are under investigation to explain the relation between LUTS and ED: (i) an increased Rho-kinase activation, (ii) an α-adrenergic receptor imbalance, (iii) a decrease of NOS/NO in the endothelium, (iv) atherosclerosis affecting the small pelvis and (v) an autonomic hyperactivity, each affecting simultaneously bladder, prostate and penis. According to a recent randomized trial, sildenafil has a positive effect on LUTS yet not on uroflowmetry in men with LUTS and ED. Although further trials are mandatory, phosphodiesterase-5 inhibitors might play a role in the management of LUTS in the future. α-Blockers have no relevant effect on erectile function, tamsulosin leads to retrograde ejaculation in up to 10%. 5α-Reductase inhibitors are associated with ED, loss of libido and reduction of ejaculate volume in up to 10%. Transurethral and open prostatectomy induce retrograde ejaculation in up to 90% of patients while their impact on erectile function is still controversially discussed. Minimal invasive treatment options (laser prostatectomy, transurethral microwave thermotherapy) have a lower rate of retrograde ejaculation in the range of 20–70%. LUTS and ED are strongly linked although the exact mechanism is poorly understood. Men seeking for help for LUTS/benign prostatic hyperplasia should be assessed for different aspects of sexual dysfunction and informed regarding the impact of medication and surgery on sexual health.
Introduction
Until recently, the association between lower urinary tract symptoms (LUTS) and erectile dysfunction (ED) has been attributed to the underlying bias age. This is emphasized by the fact that in the vast majority of reviews and guidelines on ED, LUTS were not considered as an independent risk factor. In fact, both entities belong to the most frequent urologic disorders and a variety of recent large-scale epidemiological studies analysing 1200-12 000 men have convincingly documented an age-independent relationship between LUTS and ED leading to a new paradigm in the fields of research, diagnosis and treatment.
Despite the fact that the underlying pathophysiology is still poorly understood, several theories have been elaborated to link both disorders, such as the Rho-kinase pathway, α-adrenergic receptor imbalance, a decrease of NOS/NO in the endothelium, atherosclerosis and an autonomic hyperactivity. From the clinical standpoint the most important issue is the impact of surgical and medical treatment for LUTS on male sexual function. An emerging and highly interesting aspect is the positive impact of phosphodiesterase (PDE)-5-inhibitors on LUTS.