Serum soluble α-klotho in hemodialysis patients

Clin Nephrol. 2012 May;77(5):347-51. doi: 10.5414/cn107204.

Abstract

Background: The extracellular domain of klotho is cleaved and released into various extracellular fluids, such as blood, urine, and cerebrospinal fluid, as soluble α-klotho (sαKl).

Methods: We measured sαKl in 53 hemodialysis patients and 20 healthy controls to examine its role in mineral metabolism.

Results: The sαKl level of the hemodialysis patients was 430 pg/ml (386 - 540 pg/ml, which was lower than that of healthy controls 740 pg/ml (550 - 913 pg/ml, p < 0.01). The serum sαKl level showed a positive correlation with serum phosphorus (P) (σ = 0.33, p = 0.014), while serum corrected Ca tended to be negatively correlated with sαKl (σ = -0.26, p = 0.06). Both parameters showed the same trends in healthy subjects. However, there was no significant association between serum sαKl and age (σ= 0.21, p = 0.14), intact PTH (σ = -0.08, p= 0.55), whole PTH (σ = -0.08, p = 0.59), or FGF23 (σ = -0.07, p = 0.62). Multiple regression analysis showed that P was independently associated with the serum sαKl levels (total adjusted R2 = 0.18, p = 0.02).

Conclusions: The sαKl level was lower in hemodialysis patients than in healthy persons. Serum P level was independently associated with the serum sαKl level.

MeSH terms

  • Adult
  • Aged
  • Biomarkers / blood
  • Calcium / blood
  • Case-Control Studies
  • Down-Regulation
  • Female
  • Fibroblast Growth Factor-23
  • Glucuronidase / blood*
  • Humans
  • Japan
  • Kidney Failure, Chronic / blood*
  • Kidney Failure, Chronic / therapy*
  • Klotho Proteins
  • Male
  • Middle Aged
  • Multivariate Analysis
  • Phosphorus / blood
  • Regression Analysis
  • Renal Dialysis*

Substances

  • Biomarkers
  • FGF23 protein, human
  • Phosphorus
  • Fibroblast Growth Factor-23
  • Glucuronidase
  • Klotho Proteins
  • Calcium