title: Serum β-trace protein and risk of mortality in incident hemodialysis patients.
abstract: OBJECTIVE
  Residual kidney function in dialysis patients is associated with better survival, but there are no simple methods for its assessment. β-Trace protein is a novel endogenous filtration marker of kidney function that is not removed during hemodialysis and may serve as a marker for residual kidney function similar to serum creatinine in patients not on dialysis. The objective of this study was to determine the association of serum β-trace protein with mortality in incident hemodialysis patients.
  
  
  METHODS
  Serum β-trace protein was measured in baseline samples from 503 participants of a national prospective cohort study of incident dialysis patients with enrollment during 1995-1998 and follow-up until 2004. Outcomes were all-cause and cardiovascular disease mortality analyzed using Cox regression adjusted for demographic, clinical, and treatment factors.
  
  
  RESULTS
  Serum β-trace protein levels were higher in individuals with no urine output compared with individuals with urine output (9.0±3.5 versus 7.6±3.1 mg/L; P<0.001). There were 321 deaths (159 deaths from cardiovascular disease) during follow-up (median=3.3 years). Higher β-trace protein levels were associated with higher risk of mortality. The adjusted hazard ratio and 95% confidence interval for all-cause mortality per doubling of serum β-trace protein was 1.36 (1.09-1.69). The adjusted hazard ratios (95% confidence intervals) for all-cause mortality in the middle and highest tertiles compared with the lowest tertile were 0.95 (0.69-1.32) and 1.72 (1.25-2.37). Similar results were noted for cardiovascular disease mortality.
  
  
  CONCLUSIONS
  The serum level of β-trace protein is an independent predictor of death and cardiovascular disease mortality in incident hemodialysis patients.
authors: Division of Nephrology, Johns Hopkins University School of Medicine, 301 Mason Lord Drive, Suite 2500, Baltimore, MD 21224-2780, USA. tshafi@jhmi.edu
authors: Tariq
authors: T
authors: Shafi
authors: Rulan S
authors: RS
authors: Parekh
authors: Bernard G
authors: BG
authors: Jaar
authors: Laura C
authors: LC
authors: Plantinga
authors: Pooja C
authors: PC
authors: Oberai
authors: John H
authors: JH
authors: Eckfeldt
authors: Andrew S
authors: AS
authors: Levey
authors: Neil R
authors: NR
authors: Powe
authors: Josef
authors: J
authors: Coresh
mesh_terms: D000328:Adult; D000368:Aged; D015415:Biomarkers / Q000097:blood; D002318:Cardiovascular Diseases / Q000097:blood / Q000201:enzymology / Q000401:mortality*; D002423:Cause of Death; D016009:Chi-Square Distribution; D005260:Female; D006801:Humans; D015994:Incidence; D019746:Intramolecular Oxidoreductases / Q000097:blood*; D007668:Kidney / Q000201:enzymology / Q000503:physiopathology; D007676:Kidney Failure, Chronic / Q000097:blood / Q000201:enzymology / Q000401:mortality / Q000503:physiopathology / Q000628:therapy*; D016014:Linear Models; D054834:Lipocalins / Q000097:blood*; D008297:Male; D008875:Middle Aged; D016016:Proportional Hazards Models; D011446:Prospective Studies; D006435:Renal Dialysis / Q000009:adverse effects / Q000401:mortality*; D018570:Risk Assessment; D012307:Risk Factors; D013997:Time Factors; D014481:United States / Q000453:epidemiology; D015854:Up-Regulation
chemical_list: D015415:Biomarkers; D054834:Lipocalins; D019746:Intramolecular Oxidoreductases; C022466:prostaglandin R2 D-isomerase