The Causal Relationship Between Psoriasis and Urolithiasis: A Two-Sample Bidirectional Mendelian Randomization Study

Objective To investigate the causal relationship between psoriasis and urolithiasis using Mendelian randomisation(MR).Methods The data set comprised 483174 patients with psoriasis and 484598 patients with urolithiasis, sourced from the genome-wide association study database. The urolithiasis cohort included patients with kidney stones, ureteral stones and bladder stones. The primary analytical method used to assess the causal relationship between psoriasis and urolithiasis was the inverse variance weighting (IVW) method, which provided a P-value, dominance ratio and 95% confidence interval. A sensitivity analysis was conducted using the leave-one-out method, while a multiplicity analysis was performed with the MR-Egger method. Additionally, Cochran Q was employed to detect heterogeneity. Furthermore, reverse Mendelian randomization was conducted to examine the potential causal relationship between urolithiasis and psoriasis.Results The results of the MR analysis showed a positive causal association between psoriasis and urolithiasis [OR=1.023, 95%CI(1.0015,1.0447), P=0.0357]; the results of the reverse MR analysis showed that urolithiasis did not increase the risk of psoriasis [OR=1.0187, 95%CI(0.9084,1.1421), P=0.7527]. The results of the sensitivity analyses were robust, the funnel plots were not biased and there was no heterogeneity, pleiotropy or reverse causality in the results (all P>0.05).Conclusion The results of this study provide evidence for a causal association between psoriasis and the development of urolithiasis, and that psoriasis may increase the risk of developing urolithiasis, but no evidence was found that urolithiasis contributes to the increased risk of psoriasis.