Kamińska J, Stopiński M, Mucha K, et al. - Researchers examined the association of osteopontin (OPN), osteocalcin (OC), osteoprotegerin (OPG) and fibroblast growth factor 23 with clinical features as well as assessed their ability to predict mortality in patients with different chronic kidney disease (CKD) stages. Patients with end-stage renal disease (38 ESRD), CKD stages 3 and 4 (19 CKD3-4) and non-CKD controls (19), respectively, were included. Significant rise in the levels of serum OPN, OC and OPG was observed along with kidney disease progression. A significant positive correlation among these proteins was identified. A significant link of serum OPG with an elevated risk of death was observed in patients with CKD3-4 or ESRD. Findings thus demonstrate an association between single measurement of osteoprotegerin and 5-year all-cause mortality in patients with CKD3-4 or ESRD. Evaluating its level, preferably in combination with calcium score, is recommended for mortality risk stratification of CKD patients.