title: Associations of endogenous markers of kidney function with outcomes: more and less than glomerular filtration rate.
abstract: OBJECTIVE
  As alternative markers of kidney function are investigated for clinical and research use, understanding their specific associations with outcomes, independent of glomerular filtration rate (GFR), becomes critical.
  
  
  RESULTS
  Recent large meta-analyses have defined the relationship between GFR estimated by serum creatinine and a variety of outcomes, and numerous studies have found that cystatin C predicts outcomes more strongly than does serum creatinine. Similarly improved prediction has been found recently for novel markers, beta trace protein and beta-2 microglobulin. Only a few studies of individuals with chronic kidney disease have compared these associations between markers of kidney function to directly measured GFR. These studies have found associations between these markers and mortality, cardiovascular outcomes and kidney failure that are independent of directly measured GFR.
  
  
  CONCLUSIONS
  Novel markers of kidney function may help in diagnosis, clinical management and research in chronic kidney disease (CKD). Understanding the non-GFR determinants of specific markers and relationships of markers to risk of outcomes is necessary to make these advances.
authors.affiliation: aDivision of Nephrology, Department of Medicine bDepartment of Population Health Sciences, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin, USA.
authors.forename: Brad C
authors.initials: BC
authors.lastname: Astor
authors.forename: Sumaira
authors.initials: S
authors.lastname: Shaikh
authors.forename: Muhammad
authors.initials: M
authors.lastname: Chaudhry
mesh_terms: D015415:Biomarkers / Q000097:blood*; D003404:Creatinine / Q000097:blood; D055316:Cystatin C / Q000097:blood; D005919:Glomerular Filtration Rate; D006801:Humans; D019746:Intramolecular Oxidoreductases / Q000097:blood; D007668:Kidney / Q000378:metabolism / Q000503:physiopathology*; D007674:Kidney Diseases / Q000097:blood / Q000175:diagnosis* / Q000503:physiopathology; D054834:Lipocalins / Q000097:blood; D008954:Models, Biological; D011237:Predictive Value of Tests; D011379:Prognosis; D001613:beta 2-Microglobulin / Q000097:blood
chemical_list: D015415:Biomarkers; C525030:CST3 protein, human; D055316:Cystatin C; D054834:Lipocalins; D001613:beta 2-Microglobulin; D003404:Creatinine; D019746:Intramolecular Oxidoreductases; C022466:prostaglandin R2 D-isomerase