IV selection

SNPs associated with metabolites required p-values < 5 × 10^-8, linkage disequilibrium (r² < 0.001), Hardy-Weinberg equilibrium, and genetic distance < 10,000 kb. Each SNP was then genotyped to determine its major alleles, allele frequencies, p-values, and standard errors. Previous MR studies demonstrated the effectiveness and accuracy of model estimation when IVs are applied to high-strength models. As a precaution against bias caused by weak proxies, the F-statistic was calculated for each instrument. An F-statistic of 10 was not found for any IV. Finally, Table S1 summarizes all the data related to the SNPs in detail. The selected procedures were similar to those of a previous study [13].