Klotho-FGF23, Cardiovascular Disease, and Vascular Calcification: Black or White?

BACKGROUND: Patients affected by Chronic Kidney Disease and Mineral Bone Disorder (CKD-MBD) have a high risk of cardiovascular (CV) mortality that is poorly explained by traditional risk factors. The newest medical treatments for CKD-MBD have been associated with encouraging, but still inconsistent, improvement in CV disease complications and patient survival. A better understanding of the biomarkers and mechanisms of left ventricular hypertrophy (LVH), atherosclerosis, and vascular calcification (VC) may help with diagnosis and treatment of the organ damage that occurs secondary to CKD-MBD, thus improving survival. Recent insights about fibroblast growth factor-23 (FGF23) and its co-receptor, Klotho, have led to marked advancement in interpreting data on vascular aging and CKDMBD. CONCLUSION: This review will discuss the current experimental and clinical evidence regarding FGF23 and Klotho, with a particular focus on their roles in LVH, atherosclerosis, and VC.

Sodium Prescription in the Prevention of Intradialytic Hypotension: New Insights into an Old Concept.

BACKGROUND: Sodium prescription in patients with intradialytic hypotension remains a challenge for the attending nephrologist, as it increases dialysate conductivity in hypotension-prone patients, thereby adding to dietary sodium levels. METHODS: New sodium prescription strategies are now available, including the use of a mathematical model to compute the sodium mass to be removed during dialysis as a physiological controller. RESULTS: This review describes the sodium load of patients with end-stage renal disease on chronic hemodialysis (HD) and discusses 2 strategies to remove excess sodium in patients prone to intradialytic hypotension, namely, Profiled HD and the hemodiafiltration Aequilibrium System. CONCLUSION: The Profiled HD and Aequilibrium System trial both proved effective in counteracting intradialytic hypotension.

Calcifying circulating cells: an uncharted area in the setting of vascular calcification in CKD patients.

Vascular calcification, occurring during late-stage vascular and valvular disease, is highly associated with chronic kidney disease-mineral and bone disorders (CKD-MBD), representing a major risk factor for cardiovascular morbidity and mortality. The hallmark of vascular calcification, which involves both media and intima, is represented by the activation of cells committed to an osteogenic programme. Several studies have analysed the role of circulating calcifying cells (CCCs) in vascular calcification. CCCs are bone marrow (BM)-derived cells with an osteogenic phenotype, participating in intima calcification processes and defined by osteocalcin and bone alkaline phosphatase expression. The identification of CCCs in diabetes and atherosclerosis is the most recent, intriguing and yet uncharted chapter in the scenario of the bone-vascular axis. Whether osteogenic shift occurs in the BM, the bloodstream or both, is not known, and also the factors promoting CCC formation have not been identified. However, it is possible to recognize a common pathogenic commitment of inflammation in atherosclerosis and diabetes, in which metabolic control may also have a role. Currently available studies in patients without CKD did not find an association of CCCs with markers of bone metabolism. Preliminary data on CKD patients indicate an implication of mineral bone disease in vascular calcification, as a consequence of functional and anatomic integrity interruption of BM niches. Given the pivotal role that parathyroid hormone and osteoblasts play in regulating expansion, mobilization and homing of haematopoietic stem/progenitors cells, CKD-MBD could promote CCC formation.