工具变量选择结果解析：四种暴露因素遗传SNP筛选与F统计量验证

3.2 Instrumental Variable Selection Results After screening, we obtained independent genetic instrumental variables for the four exposure factors. Specifically, glutamine retained 39 independent SNPs, citrulline retained 3 independent SNPs, testosterone retained 170 independent SNPs, and lactic acid retained 12 independent SNPs. The F-statistics for all SNPs were greater than 10, indicating the absence of weak instrument bias. The ranges and means of the F-statistics for each exposure factor are as follows: glutamine (range: 27.86 to 2187.39, mean: 127.05), citrulline (range: 29.04 to 42.63, mean: 35.42), testosterone (range: 27.86 to 1185.69, mean: 83.63), and lactic acid (range: 29.95 to 171.34, mean: 67.12). Detailed information on the instrumental variables for each exposure factor is provided in Supplementary Table S1.