Genetically Predicted Body Composition and Risk of Surgical Site Infection: A Mendelian Randomization Study

This study employed uni-variable and multi-variable Mendelian randomization (MVMR) analyses, utilizing publicly available genome-wide association study (GWAS) data, to assess the causal relationship between body composition measures such as body mass index (BMI), waist circumference (WC), and the occurrence of surgical site infection (SSI). GWAS summary statistical data were obtained for BMI, WC, and SSI from the MRC Integrated Epidemiology Unit (MRC-IEU) database, inverse variance weighted (IVW) method was used as the main analysis, and supplement sensitivity analysis (including heterogeneity test, pleiotropy analysis, leave-one-out analysis, and Mendelian Randomization Pleiotropy RESidual Sum and Outlier (MR-PRESSO)) was used to check the robustness of the results. The MR analysis showed that the increase in BMI and WC predicted by genes had a substantial causal effect on the incidence of SSI (IVW: odds ratio [OR] = 1.003, 95% confidence interval [CI] = 1.002-1.004, p < 0.001; IVW: OR = 1.003, 95% CI = 1.002-1.005, p < 0.001), respectively, and the MVMR analysis showed that after jointly incorporating smoking and alcohol parameters, the impact of BMI and WC on SSI remained substantial (OR = 1.003, 95% CI = 1.002-1.004, p < 0.001; OR = 1.004, 95% CI = 1.002-1.005, p < 0.001). We further support the causal relationship between increased body composition including BMI and WC and the occurrence of SSI, highlighting the importance of SSI prevention in patients with obesity. Further research is required to mitigate the occurrence of surgical incisions in patients with obesity in the future.