2.3 Genetic instruments
Genetic IVs were chosen as independent single nucleotide polymorphisms (SNPs) with genome-wide significance (defined as p < 1×10-5). To ensure independence among IVs for each exposure, we applied an LD threshold, r2 < 0.001, for SNPs within a 10,000 kb distance. We assessed the strength of the genetic instruments using F-statistics, with a strong instrument defined as an F-statistic > 10. Furthermore, we eliminated SNPs associated with potential confounding factors, such as height, white blood cell count, and body mass index (BMI), to meet the independence assumption of MR. We utilized the PhenoScannerV2 tool (http://www.phenoscanner.medschl.cam.ac.uk/) for this purpose (12, 13).