title: Urinary NGAL levels before and after coronary angiography: a complex story.
abstract: BACKGROUND
  We describe urinary neutrophil gelatinase-associated lipocalin (uNGAL) values in association with clinical characteristics and urinary parameters in adults undergoing coronary angiography.
  
  
  METHODS
  This is an observational study of consecutive patients who underwent elective coronary angiography during a 4-month period in a large urban tertiary care hospital.
  
  
  RESULTS
  One hundred and thirteen patients were enrolled, and 100 had sufficient data to be included in the analyses. A large range of preprocedural uNGAL levels were observed (range 1-269 ng/mg Cr). Median preprocedural uNGAL was 8 ng/mg Cr. Age (P = 0.009), serum creatinine (P = 0.077) and albumin excretion (P = 0.009) were significant predictors of baseline uNGAL. Half the cohort demonstrated an increase and half a decrease in the absolute values of uNGAL after angiography, irrespective of preprocedural levels.
  
  
  CONCLUSIONS
  We observed variable, but relatively low absolute levels of uNGAL prior to angiography in this 'cardiac' cohort. Only age, serum creatinine and albumin excretion could explain some of this variability. When designing studies of at-risk individuals where uNGAL may be used as a marker for acute kidney injury, this variability should be taken into account.
authors.affiliation: Division of Nephrology, Department of Medicine, University of British Columbia, Vancouver, British Columbia, Canada.
authors.forename: Catherine L
authors.initials: CL
authors.lastname: Weber
authors.forename: Matthew
authors.initials: M
authors.lastname: Bennett
authors.forename: Lee
authors.initials: L
authors.lastname: Er
authors.forename: Michael T
authors.initials: MT
authors.lastname: Bennett
authors.forename: Adeera
authors.initials: A
authors.lastname: Levin
mesh_terms: D000209:Acute-Phase Proteins / Q000652:urine*; D000328:Adult; D000368:Aged; D015415:Biomarkers / Q000652:urine*; D015331:Cohort Studies; D017023:Coronary Angiography; D003404:Creatinine / Q000652:urine*; D005260:Female; D006331:Heart Diseases / Q000000981:diagnostic imaging* / Q000652:urine*; D006801:Humans; D000071068:Lipocalin-2; D054834:Lipocalins / Q000652:urine*; D008297:Male; D008875:Middle Aged; D011518:Proto-Oncogene Proteins / Q000652:urine*; D012680:Sensitivity and Specificity
chemical_list: D000209:Acute-Phase Proteins; D015415:Biomarkers; C489506:LCN2 protein, human; D000071068:Lipocalin-2; D054834:Lipocalins; D011518:Proto-Oncogene Proteins; D003404:Creatinine