Affiliation:
1. Clinical School of Medicine, Chengdu University of Traditional Chinese Medicine , Chengdu 610075 , China
2. Traditional Chinese Medicine Department, Chongqing General Hospital , Chongqing 401121 , China
3. Health Management Center, Hospital of Chengdu University of Traditional Chinese Medicine , Chengdu 610075 , China
4. Department of Urology, Chengdu Pidu District Hospital of Traditional Chinese Medicine , Chengdu 611730 , China
5. Department of Urology, No.3 Affiliated Hospital of Chengdu University of Traditional Chinese Medicine (West District) , Chengdu 611730 , China
Abstract
Abstract
Background
Observational studies have indicated a high prevalence of erectile dysfunction (ED) among patients with inflammatory bowel disease (IBD), but a definitive causal relationship remains unestablished.
Aim
The primary aim of this study was to assess the potential causal relationship between IBD and ED using Mendelian randomization (MR) analysis.
Methods
We obtained statistical data for 2 subtypes of IBD, ulcerative colitis (UC) and Crohn's disease (CD), as well as for ED, from publicly available genome-wide association studies (GWASs). Subsequently, a 2-sample MR analysis was conducted using these datasets. 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's Q test and evaluated pleiotropy with the MR-Egger intercept test. To identify potential influential single nucleotide polymorphisms, we employed a leave-one-out analysis. Additionally, outliers were identified using the MR-PRESSO method.
Outcomes
The study outcomes encompassed results from 3 MR analyses, namely IVW, MR-Egger, and weighted median, along with sensitivity analyses involving Cochran's Q test, the MR-Egger intercept test, leave-one-out analysis, and the MR-PRESSO method.
Results
There was no causal effect of UC and CD on ED in the MR analysis (IVW P > .05). Results of complementary methods were consistent with those of the IVW method. The results of sensitivity analyses supported our conclusion, and no directional pleiotropy was found.
Clinical Implications
Genetically, despite the absence of a causal link between IBD and ED according to MR analysis, we must emphasize the elevated ED prevalence among IBD patients in observational studies, with particular consideration for the influence of negative emotions on erectile function.
Strengths & Limitations
This study is the inaugural application of a 2-sample MR analysis using extensive GWAS datasets to evaluate the causal relationship between IBD and ED, effectively mitigating biases stemming from confounding factors and reverse causality often present in observational studies. Nevertheless, it is imperative to exercise caution when drawing conclusions due to inherent limitations in GWAS data, encompassing factors like samples overlap, gender categorization, population ancestry, and the persistent ambiguity surrounding the precise functionality of specific single nucleotide polymorphisms.
Conclusions
MR analysis did not provide genetic-level evidence supporting a direct causal relationship between IBD (UC and CD) and ED.
Publisher
Oxford University Press (OUP)
Subject
Behavioral Neuroscience,Urology,Dermatology,Reproductive Medicine,Endocrinology,Endocrinology, Diabetes and Metabolism,Psychiatry and Mental health