We defined serum creatinine-based CKD (CKDcr) and serum cystatin C-based CKD (CKDcys) as glomerular filtration rate <60 mL/min/1.73 m2, estimated using serum creatinine or cystatin C, and/or dipstick proteinuria ≥1+. Here, CST3 is linked to chronic kidney disease.