No causal effect between prostatitis and erectile dysfunction: Insights from a 2-sample bidirectional Mendelian randomization study

Both prostatitis and erectile dysfunction (ED) are common diseases in andrology. The epidemiologic evidence indicates that prostatitis is associated with ED, but controversy still remains. This study aims to utilized publicly available genetic data and Mendelian randomization (MR) to investigate the causal effect between prostatitis and ED. We obtained statistical data for prostatitis and ED from the FinnGen consortium. By utilizing single-nucleotide polymorphisms (SNPs) as genetic instrument variables, we conducted a 2-sample bidirectional MR analysis. The primary MR analysis utilized the inverse variance weighted (IVW) method, complemented by secondary analyses employing MR-Egger and weighted median methods. Furthermore, we assessed heterogeneity using Cochran Q-test and evaluated pleiotropy with the MR-Egger intercept test. To identify potential influential SNPs, we employed a leave-one-out analysis. Additionally, outliers were identified using the Mendelian randomization-pleiotropy residual sum and outlier methods (MR-PRESSO). The IVW results indicated that there was no clear causal effect of prostatitis on ED (odds ratio [OR] = 1.132, 95% confidence interval [CI] = 0.937-1.367, P = .199) and there was no clear causal effect of ED on prostatitis (OR = 1.044, 95% CI: 0.96-1.135, P = .311). This MR study showed that there was no clear causal effect between prostatitis and ED in Europeans in the genetic prediction.