CRP and peripheral arterial disease: After logistic regression, a covariate-adjusted ROC analysis was performed using the same covariates detected using the stepwise method (creatinine, C-reactive protein, total choline), 20.0 mL/min for LDF-Plantar-Qb were defined as the cut-off points for PAD (Additional file 2: Table S4) (area under the curve: 0.90 in LD) (Fig. 4).