However, Branderburg et al. [23] and Valenzuela et al. [24] reported S-Klotho not to be related to cardiovascular disease and all-cause mortality in a cohort of elderly persons with normal and mildly impaired kidney function, although they were at high risk of suffering a future cardiovascular event [23] and in elderly patients with chronic kidney disease [24], respectively. Here, KL is linked to chronic kidney disease.