KL and heart failure: Circulating levels of Ca, IP, and 25(OH)D were also reported to be associated with cardiovascular risk [44], [45] and elevated PTH levels were associated with left ventricular mass and severity of heart failure [39], [46]; therefore, one should confirm, as has been done in the current study, whether the observed relationship between FGF23/α-Klotho and cardiac abnormality is mediated or confounded by the above-mentioned variables, whose levels are related to FGF23/α-Klotho levels [47], [48].