BackgroundWe aimed to investigate the prevalence, relative risk factors, and the impact on the health-related quality of life (HRQoL) of benign prostatic obstruction (BPO) with coexisting overactive bladder (OAB) in men aged over 50 and living in Shanghai Pudong New Area.MethodsUsing a multi-stage sampling and descriptive epidemiological method, 1632 men were selected from among the general population. Participants completed an evaluation of lower urinary tracts symptoms (LUTS), including international prostate symptom score (IPSS) and quality of life (QoL) questionnaires. Erectile function was assessed using the International Index of Erectile Function-5 (IIEF-5) questionnaire. In addition, the Overactive Bladder Symptom Score (OABSS) and King’s health questionnaire (KHQ) were used to assess the impact of BPO with coexisting OAB on the HRQoL. Maximum flow rate (Qmax), postvoid residual urine volume (PVR) and prostate-specific antigen (PSA) were also recorded.ResultsA total of 1476 men with complete data were analyzed. The overall prevalence of BPO with coexisting OAB was 39.6%. Age and prostate volume were associated risk factors for BPO with coexisting OAB. In addition, BPO with coexisting OAB negatively impacted the HRQoL, with increased IPSS, QoL, OABSS, and KHQ scores and decreased IIEF-5 scores compared to that in patients with BPO without OAB.ConclusionsQmax, PVR and serum PSA did not predict whether the patients had a combined BPO + OAB or not. The prostate volume and age were associated risk factors for BPO with coexisting OAB. BPO is a progressive disease and may be one of the risk factors for OAB.