CRP and chronic kidney disease: The risk of individuals in the highest tertile of log(sTfR) was compared with the risk of individuals in the second tertile of log(sTfR) by subgroups stratified according to age (20–29, 30–39, or 40–49 years old), DM (yes or no), hypertension (yes or no), CKD (yes or no), cancer (yes or no), haemoglobin (< 12 or ≥ 12 g/dL), ferritin (< 30 or ≥ 30 ng/mL), and CRP (< 0.3 or ≥ 0.3 mg/dL).