FGF-23 and Klotho levels were not different between smokers and non-smokers.Patients in the CKD group on conservative treatment had higher serum P thannon-smokers (p = 0.026) even after adjusted for renalfunction (p = 0.079), gender (p = 0.145)and age (p = 0.986). This evidence concerns the gene KL and chronic kidney disease.