In our current study, we observed that serum FGF23 levels and FGF23/α-klotho ratio were positively correlated with carotid atherosclerosis in T2DM patients, while serum α-klotho levels were negatively associated with carotid atherosclerosis in T2DM patients, suggesting that FGF23 might be an independent risk factor for adverse cardiovascular events and that α-klotho might be a protective factor, likewise, FGF23/α-klotho ratio may also be a novel indicator for predicting T2DM combined with atherosclerosis [48]. Here, KL is linked to type 2 diabetes mellitus.