Background/Aim: The role of androgen in the modulation of voiding function is still uncertain. The aim of this study was to evaluate the association of androgen deprivation therapy (ADT) and overactive bladder (OAB) in men in a population-based cohort. Materials and Methods: This study examined the records of newly-diagnosed prostate cancer subjects receiving ADT only in the Taiwan National Health Insurance Research Database in the years between 2001 and 2007.As controls men without cancer were selected and divided into three groups, 1) benign prostate hyperplasia treated with an alpha-blocker (BPH-alpha blocker), 2) BPH treated with a 5alpha reductase inhibitor (BPH-5ARI) and 3) healthy controls. OAB events were censored by definition of drug prescriptions for more than one month and risk analysis among each group was performed. Results: The healthy control group had decreased risk of OAB compared to the prostate cancer group and the BPH-5ARI group showed a higher risk of OAB than the prostate cancer group. Subgroup analysis showed that independently of age or comorbidities, the prevalence of OAB was significantly lower in the healthy control group. Moreover, the cumulative incidence of OAB showed a time-dependent pattern with a significant increase after ADT for 5 years. Conclusion: Androgen deprivation in prostate cancer patients was associated with an increased risk of OAB that was treatment duration-dependent. This result is consistent with an inhibitory role of androgen in the modulation of male voiding function.Sex hormones including androgen and estrogen bind to steroid receptors that are widely distributed in human tissues (1, 2). In genitourinary tract, sex hormones not only control the appearance and function of sex organs, but may also influence lower urinary tract function (3). Our previous human population cohort studies as well as experimental studies on female rats suggested that estrogen may influence the voiding function in females (4, 5). However, the role of androgen in the modulation of male voiding functions is less certain. Epidemiological studies showed that aging which is accompanied by decreased serum testosterone levels (6, 7) is also associated with increased prevalence of overactive bladder (OAB). We also showed that orchiectomy decreased the volume threshold for inducing micturition in a rat model (8). Based on current evidence, serum testosterone seems to play a role in the modulation of voiding function in men (9). However, a relationship between serum testosterone level and OAB has not been established.In this study, a nationwide population-based insurance database was used to examine a possible link between androgen deprivation therapy (ADT) and OAB in prostate cancer patients. The data were compared with data obtained from healthy controls and from patients with benign prostate hyperplasia (BPH).
Materials and MethodsData sources.