Marthi et al. (2018) carried out a meta-analysis that looked at thirty-four studies: 17 with the general population, nine with CKD non-dialysis patients and eight with the dialysis population. Overall, when comparing participants classified by FGF-23 quartiles, in the top versus bottom third of baseline FGF-23 concentration there was a 70% increased risk of all-cause mortality and 42% increased risk of cardiovascular mortality (Marthi et al., 2018). Here, FGF23 is linked to chronic kidney disease.