title: Race-specific association of lipoprotein(a) with vascular access interventions in hemodialysis patients: the CHOICE Study.
abstract: BACKGROUND
  Elevated serum levels of lipoprotein(a) [Lp(a)] and low molecular weight apolipoprotein(a) [apo(a)] isoforms are associated with atherothrombotic disease in the general population and in patients with kidney failure. Lp(a) may be more atherothrombotic in whites than in blacks. Data on the relation of Lp(a) and apo(a) isoform size to hemodialysis vascular access complications are limited.
  
  
  METHODS
  We analyzed the intervention-free survival of the first arteriovenous (AV) access among 215 white and 112 black incident hemodialysis patients participating in the CHOICE Study, a national multicenter prospective cohort study.
  
  
  RESULTS
  Median levels of Lp(a) protein were higher among blacks than whites (81.0 versus 37.5 nmol/L; P < 0.001) and inversely correlated with apo(a) isoform size (r = -0.57; P < 0.001). The incidence rate of access interventions was much higher in synthetic grafts (N = 193) than native fistulae (N = 134; 1.0 vs. 0.5 interventions per access-year; P < 0.001) and in patients with kidney failure primarily due to diabetes mellitus (N = 161) than others (N = 166; 0.9 vs. 0.6; P < 0.01), but did not differ by race. Blacks in the highest race-specific Lp(a) quartile (>145 nmol/L) had a significantly higher incidence rate than other blacks (1.4 vs. 0.7; P = 0.04), whereas no association was found in whites. The association in blacks remained after adjustment for access type and other characteristics (relative hazard = 1.68; 95% confidence interval: 0.98 to 2.86). No association was found with apo(a) isoform size in either race.
  
  
  CONCLUSIONS
  Elevated Lp(a) may be a risk factor for arteriovenous access complications among black hemodialysis patients. Future studies should explore this possibility and be adequately powered to allow race-specific analyses.
authors.affiliation: Welch Center for Prevention, Epidemiology, and Clinical Research, The Johns Hopkins University, 2024 East Monument Street, Baltimore, MD 21205, USA. bastor@jhsph.edu
authors.forename: Brad C
authors.initials: BC
authors.lastname: Astor
authors.forename: Joseph A
authors.initials: JA
authors.lastname: Eustace
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Klag
authors.forename: Neil R
authors.initials: NR
authors.lastname: Powe
authors.forename: J Craig
authors.initials: JC
authors.lastname: Longenecker
authors.forename: Nancy E
authors.initials: NE
authors.lastname: Fink
authors.forename: Santica M
authors.initials: SM
authors.lastname: Marcovina
authors.forename: Josef
authors.initials: J
authors.lastname: Coresh
mesh_terms: D000328:Adult; D000368:Aged; D001166:Arteriovenous Shunt, Surgical / Q000009:adverse effects*; D044383:Black People; D001807:Blood Vessel Prosthesis / Q000009:adverse effects; D015331:Cohort Studies; D005260:Female; D006801:Humans; D017270:Lipoprotein(a) / Q000097:blood*; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D011446:Prospective Studies; D006435:Renal Dialysis; D016019:Survival Analysis; D014652:Vascular Diseases / Q000209:etiology* / Q000628:therapy*; D044465:White People
chemical_list: D017270:Lipoprotein(a)