In the CKD population (Fig. 9), Klotho was linearly related to WBC, Neu, NLR, PLR, PIV, SII, TG, eGFR, serum urea nitrogen and uric acid (all P-nonlinear > 0.05) and non-linearly related to SIRI and serum creatinine (all P-nonlinear < 0.05). Here, KL is linked to chronic kidney disease.