The potential roles of FGF23 and Klotho in the prognosis of renal and cardiovascular diseases.

Fibroblast growth factor (FGF) 23 and Klotho are two factors associated with several metabolic disorders. Similar to humans, accelerated aging processes characterized by chronic vascular disease, bone demineralization, skin atrophy and emphysema have been recognized in FGF23-null mice and Klotho-deficient mice. The role of these factors in the control of mineral metabolism homeostasis have been shown recently, particularly at the level of parathyroid cells and also in modulating active vitamin D production, two phenomena which are relevant in the presence of chronic kidney disease. In addition, the hormonal affect of circulating FGF23 and Klotho proteins on vascular reactivity, either directly on endothelial cell functions or indirectly by modulating the brain endothelin-1-dependent sympathetic nervous system activity, has contributed to understanding their role in the pathophysiology of hypertension and atherosclerotic vasculopathies. Consequently, very recent clinical investigations seem to confirm the involvement of Klotho in modulating the severity and prognosis of human cardiovascular (CV) disorders and longevity. The present review reports data related to the possible interactive effects of Klotho and FGF23 on the prognosis of renal and CV diseases.