ALB and peripheral arterial disease: We performed subgroup analysis to explore the association between indoxyl sulfate and incident PAD in the cohort stratified by sex, albumin (≥3.8 vs. <3.8 g/dL), normalized protein nitrogen appearance (nPCR) (≥1.0 vs. <1.0 g/kg/day), systolic BP (>140 vs. ≤140 mmHg), and the TC:HDL-C ratio (>5.0 vs. ≤5.0) (Figure 2).