The association of serum soluble Klotho levels and residual diuresis and overhydration in peritoneal dialysis patients

Abstract

Background. Klotho, originally identified as an anti-aging factor, is a transmembrane protein expressed in the kidney. It has been reported that Klotho deficiency could be associated with a loss of residual renal function and cardiovascular complications in peritoneal dialysis (PD) patients. Objectives.The main aim of the study was to evaluate whether serum levels of Klotho correlate with residual diuresis and hydration status in PD patients.Material and methods. The cross-sectional study involved 57 PD patients ≥18 years of age who had been on PD ≥ 3 months. Serum Klotho was measured using high-sensitivity enzyme-linked immunosorbent assay (ELISA). Hydration status was assessed with bioimpedance analysis (BIA).Results. Serum levels of soluble Klotho ranged from 100 pg/mL to 700 pg/mL. The patients were divided into 2 subgroups, with Klotho levels below and above the median (260 pg/mL). The data revealed a tendency for lower residual diuresis (1.3 ±1.0 L vs 1.8 ±0.8 L; p = 0.055) in patients with lower levels of Klotho in serum. Serum Klotho correlated negatively with overhydration according to BIA (r = −0.27; p = 0.044) and positively with residual diuresis (r = 0.26; p = 0.045). Conclusions.Soluble Klotho correlates inversely with hydration status in BIA. Residual urine output, but not dialysis parameters, could be associated with the levels of serum soluble Klotho in PD patients.

The controversy of klotho as a potential biomarker in chronic kidney disease

“…It has been reported that sKlotho undergoes a transcytosis process and reaches the tubular lumen ( Hu et al, 2016 ). This may explain the fact that serum sKlotho was inversely associated with urine output other than with the remaining kidney function in patients undergoing peritoneal dialysis ( Sikorska et al, 2019 ). Tubular injury decreased sKlotho clearance and was associated with an increased serum sKlotho level in specific CKD models, such as DKD ( Bob et al, 2019 ).…”