Appraising the causal relationship between kidney function and hearing performance: a two-sample Mendelian randomization study

> 0.05). Although the IVW estimate for eGFR and left-ear SRT approached nominal significance and some secondary analyses showed nominal associations, these findings were inconsistent across methods and did not meet our criteria for robust causal inference. Reverse Mendelian randomization analyses also showed no significant associations. Sensitivity analyses showed no evidence of directional horizontal pleiotropy, and outlier correction did not materially change the results. This study provides no robust genetic evidence supporting a causal relationship between genetically predicted kidney function traits and hearing function, as measured by speech reception threshold, in either direction under the current MR framework. The observed epidemiological association may instead reflect shared systemic, developmental, or environmental mechanisms.