title: Soluble Klotho levels in diabetic nephropathy: relationship with arterial stiffness.
abstract: In this cross-sectional study, we investigate the relationship between soluble Klotho (s-Klotho) levels, markers of bone mineral metabolism and arterial stiffness in 109 diabetic nephropathy patients (median age 61.00± 9.77 years) and 32 healthy controls (median age 49.23 ± 7.32 years).
  
  
  
  Blood samples were collected to measure the levels of s-Klotho, and FGF23, serum creatinine, Calcium (Ca), Phosphorus (P), 25-hydroxyvitamin D3 (25hD) and parathyroid hormone (PTH). Pulse wave velocity (PWV) and blood pressure were also measured using a combined monitor.
  
  
  
  s-Klotho, FGF23 and PTH levels were significantly higher and 25hD was significantly lower in the patients than in controls (p < 0.001). Systolic blood pressure, pulse pressure and PWV were also significantly higher in the patients (p < 0.001). s-Klotho, FGF23 and 25hD levels significantly varied between sub-groups according to CKD stages, defined according to the CKD epidemiology collaboration equation. A strong positive correlation was found between s-Klotho and FGF23 (r = 0.768, p = 0.001) levels, but not with other bone mineral metabolism, blood pressure or arterial stiffness parameters. Creatinine levels significantly differed (p = 0.009) between three s-Klotho-level sub-groups, with the high creatinine levels in the sub-group with the lowest s-Klotho levels and estimated glomerular filtration rate (eGFR).
  
  
  
  There was no correlation between eGFR and s-Klotho levels. Arterial stiffness increased in CKD but was not related to s-Klotho or FGF23 levels. Among all parameters, FGF23 levels had the greatest effect on s-Klotho levels.
authors.affiliation: Division of Nephrology, Internal Medicine, Antalya Training and Research Hospital, Antalya, Turkey. aycainci2004@hotmail.com.
authors.forename: A
authors.initials: A
authors.lastname: Inci
authors.forename: F
authors.initials: F
authors.lastname: Sari
authors.forename: R
authors.initials: R
authors.lastname: Olmaz
authors.forename: M
authors.initials: M
authors.lastname: Coban
authors.forename: S
authors.initials: S
authors.lastname: Dolu
authors.forename: M
authors.initials: M
authors.lastname: Sarikaya
authors.forename: H Y
authors.initials: HY
authors.lastname: Ellidag
mesh_terms: D000368:Aged; D016022:Case-Control Studies; D003430:Cross-Sectional Studies; D003928:Diabetic Nephropathies / Q000201:enzymology*; D005260:Female; D000089703:Fibroblast Growth Factor-23; D005346:Fibroblast Growth Factors / Q000097:blood; D005966:Glucuronidase / Q000097:blood*; D006801:Humans; D008297:Male; D008875:Middle Aged; D063177:Pulse Wave Analysis; D059289:Vascular Stiffness
chemical_list: C000717427:FGF23 protein, human; D005346:Fibroblast Growth Factors; D000089703:Fibroblast Growth Factor-23; D005966:Glucuronidase