title: Soluble α-klotho as a novel biomarker in the early stage of nephropathy in patients with type 2 diabetes.
abstract: OBJECTIVE
  Although α-klotho is known as an anti-aging, antioxidant, and cardio-renal protective protein, the clinical implications of soluble α-klotho levels in patients with diabetes have not been evaluated. Therefore, this study evaluated whether plasma and urinary α-klotho levels are associated with albuminuria in kidney disease in diabetes.
  
  
  METHODS
  A total of 147 patients with type 2 diabetes and 25 healthy control subjects were enrolled. The plasma and urine concentrations of α-klotho were analyzed by enzyme-linked immunosorbent assay.
  
  
  RESULTS
  Plasma α-klotho (572.4 pg/mL [95% CI, 541.9-604.6 pg/mL] vs. 476.9 pg/mL [95% CI, 416.9-545.5 pg/mL]) and urinary α-klotho levels (59.8 pg/mg creatinine [95% CI, 43.6-82.0 pg/mg creatinine] vs. 21.0 pg/mg creatinine [95% CI, 9.7-45.6 pg/mg creatinine]) were significantly higher in diabetic patients than non-diabetic controls. Among diabetic patients, plasma α-klotho concentration was inversely associated with albuminuria stages (normoalbuminuria, 612.6 pg/mL [95% CI, 568.9-659.6 pg/mL], microalbuminuria, 551.8 pg/mL [95% CI, 500.5-608.3 pg/mL], and macroalbuminuria, 505.7 pg/mL [95% CI, 439.7-581.7 pg/mL] (p for trend  = 0.0081), while urinary α-klotho levels were remained constantly high with increasing urinary albumin excretion.
  
  
  CONCLUSIONS
  Soluble α-klotho levels in plasma and urine may be novel and useful early markers of diabetic renal injury.
authors.affiliation: Department of Internal Medicine, Soonchunhyang University Cheonan Hospital, Cheonan, Korea.
authors.forename: Eun Young
authors.initials: EY
authors.lastname: Lee
authors.affiliation: Department of Internal Medicine, Pusan National University Hospital, Busan, Korea.
authors.forename: Sang Soo
authors.initials: SS
authors.lastname: Kim
authors.affiliation: Biostatistical Consulting Unit, Soonchunhyang University Medical Center, Seoul, Korea.
authors.forename: Ji-Sung
authors.initials: JS
authors.lastname: Lee
authors.affiliation: Department of Internal Medicine, Pusan National University Hospital, Busan, Korea.
authors.forename: In Joo
authors.initials: IJ
authors.lastname: Kim
authors.affiliation: Department of Internal Medicine, Pusan National University Hospital, Busan, Korea.
authors.forename: Sang Heon
authors.initials: SH
authors.lastname: Song
authors.affiliation: Department of Physiology, Yonsei University Wonju College of Medicine, Wonju, Korea.
authors.forename: Seung-Kuy
authors.initials: SK
authors.lastname: Cha
authors.affiliation: Department of Physiology, Yonsei University Wonju College of Medicine, Wonju, Korea.
authors.forename: Kyu-Sang
authors.initials: KS
authors.lastname: Park
authors.affiliation: Department of Internal Medicine, Soonchunhyang University Cheonan Hospital, Cheonan, Korea.
authors.forename: Jeong Suk
authors.initials: JS
authors.lastname: Kang
authors.affiliation: Department of Internal Medicine, Yonsei University Wonju College of Medicine, Wonju, Korea.
authors.forename: Choon Hee
authors.initials: CH
authors.lastname: Chung
mesh_terms: D000328:Adult; D000368:Aged; D000419:Albuminuria; D015415:Biomarkers / Q000097:blood / Q000652:urine; D016022:Case-Control Studies; D003924:Diabetes Mellitus, Type 2 / Q000097:blood* / Q000150:complications* / Q000652:urine; D003928:Diabetic Nephropathies / Q000097:blood* / Q000473:pathology / Q000652:urine; D005260:Female; D005966:Glucuronidase / Q000097:blood* / Q000652:urine; D006801:Humans; D000090265:Klotho Proteins; D008297:Male; D008875:Middle Aged; D012307:Risk Factors
chemical_list: D015415:Biomarkers; D005966:Glucuronidase; D000090265:Klotho Proteins
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