Serum klotho level as an indicator for predicting the progression of renal function in chronic kidney disease stages 3~5

Abstract

Objective To investigate the association of serum klotho level with renal function deterioration and whether serum klotho level can be used as a predictor of progression of chronic kidney disease (CKD) into renal end point events. Methods We examined serum klotho protein level using ELISA in 261 patients with primary chronic kidney disease stages 3~5 hospitalized in our department between March and November 2015. Kaplan-Meier survival analysis was used to compare the survival time of the patients with low (< 469.26 pg/mL), medium (469.26-844.55 pg/mL) and high (≥844.55 pg/mL) levels of klotho; Cox regression analysis was performed to assess the risk factors associated with the outcomes of the patients. Results During a mean follow-up for 42.7 months, 190 (72.80%) out of the 261 patients with CKD developed renal end point events. Serum klotho level showed a significant positive correlation with estimated glomerular filtration rate (eGFR) of the patients (r=0.567, P < 0.001). The patients with different serum klotho levels had significant differences in serum levels of calcium, phosphorus, parathyroid hormone (PTH) and hemoglobin (P < 0.001). Kaplan-Meier survival analysis showed that a low serum level of klotho was associated with a shorter time for CKD to progress into renal end point events. Cox regression analysis revealed that compared with the patients with a high level of klotho, the patients with low and medium serum levels of klotho had significantly increased risks for developing renal end point events by 3.3 and 1.1 folds, respectively; after adjustment for multiple factors, the risk for renal end point events was still high in low klotho level group (2.401 times that in high klotho level group). Conclusion We confirm that serum klotho level is closely related to the occurrence of renal end point events in CKD patients, and serum klotho level is a predictor of the renal function progression in CKD patients.

Keywords

• chronic kidney disease
• klotho protein
• renal end point events