Association between chronic prostatitis and the subsequent benign prostatic hyperplasia: a population-based national cohort study

Purpose: To explore the association between chronic prostatitis (CP) and the subsequent development of benign prostatic hyperplasia (BPH). Methods: Data analyzed were medical claims of Taiwan’s National Health Insurance program. From 2010 to 2017, 3571 patients ≧20 years with CP diagnosed by certified urologists were enrolled. Patients with past BPH diagnosis and diagnosis of prostate cancer, inguinal hernia, interstitial cystitis, and urethritis in the past and within one year after the first CP diagnosis were excluded. Age-matched controls were randomly selected from all non-CP individuals of the same exclusion criteria in the study period with a CP/non-CP ratio of 1:4. The follow-up was made from the first CP diagnosis to death or the end of 2018. The endpoint was the newly diagnosed BPH. Cox proportional hazard regression model was used to estimate the hazard ratio (HR) and 95% confidence interval (CI) of BPH in association with CP. Results: Over a maximum of 8 years of follow-up, 287 (8.03%) and 258 (0.43%) BPH events were noted for the CP and non-CP group, respectively, representing a covariate adjusted HR (aHR) of 4.30 (95% CI, 3.61–5.13). Younger patients tended to suffer from higher aHRs, especially those aged 20–39 years (aHR: 11.45, 95% CI, 5.12–25.64). Conclusion: The Taiwan national health database indicated that CP patients had a significantly higher risk of developing BPH later than non-CP patients. Interestingly, the younger the CP is diagnosed (under 40), the greater the risk.