supplementary materials

This study investigated the relationship between AISI, markers of oxidative stress and MetS in US adults, using cross-sectional data from NHANES (2007–2018). MR methods were also employed to provide genetic evidence for the study and multiple approaches were adopted to ensure the robustness of the causal effects, including random-effects inverse-variance weighting (IVW), weighted median and MR-Egger regression. These findings could inform new approaches to the prevention and management of MetS in urban areas.