A Mendelian Randomization Study of the Connection Between Exogenous Hormones and Perianal Abscess in Pediatric Patients.

Background: Recent years have witnessed the hypothesis that bioavailable testosterone (BT) might be closely related to the development of inflammatory diseases, especially anal abscess (AA), a common inflammatory ailment with unclear pathogenesis. Given that AA is more prevalent among males, this study investigates the causal relationship between BT and AA. Objective: To explore the causal link between BT and AA, a Mendelian randomization (MR) study was conducted using large-scale genomic data. Materials and Methods: Utilizing genomic data from the UK Biobank and IEU OpenGWAS databases, a two-sample MR analysis was executed. Twenty-six genetic variants strongly associated with BT were selected as instrumental variables (IVs) to assess their link with AA risk. Various MR methods were employed for consistency checks, including sensitivity analyses for heterogeneity and horizontal pleiotropy. Results: Using a combination of MR methods, we identified a significant causal relationship between BT and the risk of AA. Specifically, the MR analysis revealed that higher levels of BT were associated with an increased risk of AA. Sensitivity analyses, including heterogeneity tests and assessments for horizontal pleiotropy, confirmed the robustness of these findings. The IVs used in the analysis demonstrated a strong association with BT and showed no evidence of significant heterogeneity or horizontal pleiotropy, indicating the validity of the causal inference. Conclusion: This study, employing two-sample MR for the first time, confirms a causal relationship between BT levels and the risk of AA. These findings provide preliminary evidence of the causal relationship between BT and AA and may offer new insights into the pathophysiological mechanism of AA and future therapeutic strategies.