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

Abstract

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. The main aim of the study was to evaluate whether serum levels of Klotho correlate with residual diuresis and hydration status in PD patients. 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). Serum levels of soluble Klotho ranged from 100pg/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). 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.