Mendelian randomized study reveals the causal relationship between tea drinking and cholelithiasis.

Objective To evaluate the causal relationship between tea drinking and cholelithiasis by two-way Mendelian randomization. Methods The instrumental variables for tea drinking were determined from 447 485 participants in the UK Biobank genome-wide association study (GWAS). A total of 32 single nucleotide polymorphisms (SNPs) associated with tea drinking were used for two-sample Mendelian randomized analysis to evaluate the causal relationship between tea drinking and cholelithiasis. Cholelithiasis data were obtained from GWAS data of 35 712 cholelithiasis patients and 273 442 controls publicly available from the Finnegan Alliance. In this study, inverse variance weighted (IVW) was used as the main method to estimate causality, and sensitivity analysis was carried out to ensure the robustness of the results. Finally, reverse Mendelian randomization analysis was used to verify whether there was a reverse correlation. Results There was a causal re-lationship between tea drinking and cholelithiasis. In the IVW method, each additional standard deviation (2.85 cups/day) of tea consumption reduced the risk of cholelithiasis by 26.1% (OR =0.739, 95% CI: 0.536-0.990). Similar results were obtained in weighted mode (OR=0.652, 95% CI: 0.458-0.928), but there was no evidence to prove reverse correlation (IVW: P > 0.05). Conclusion The genetic evidence provided by two-way Mendelian randomized analysis shows that the increase of tea drinking reduces the risk of cholelithiasis, but there is no evidence of reverse association. [ABSTRACT FROM AUTHOR]