title: Trajectories of kidney function decline in young black and white adults with preserved GFR: results from the Coronary Artery Risk Development in Young Adults (CARDIA) study.
abstract: BACKGROUND
  Strong racial discrepancies in end-stage renal disease exist. Whether there are race differences in kidney function loss in younger healthy persons is not well established.
  
  
  METHODS
  Longitudinal.
  
  
  METHODS
  3,348 black and white adults with at least 2 measurements of cystatin C-based estimated glomerular filtration rate (eGFRcys) at scheduled Coronary Artery Risk Development in Young Adults (CARDIA) examinations (years 10, 15, and 20).
  
  
  METHODS
  Race.
  
  
  METHODS
  We used linear mixed models to examine race differences in annualized rates of eGFRcys decline, adjusting for age, sex, lifetime exposure to systolic blood pressure >120 mm Hg, diabetes, and albumin-creatinine ratio. We used Poisson regression to compare racial differences in rapid decline (eGFRcys decline >3% per year) by study period (10-15 years after baseline examination [defining period 1] and >15-20 years after baseline examination [defining period 2]).
  
  
  RESULTS
  Mean age was 35 ± 3.6 (SD) years, and mean eGFRcys was 110 ± 20 mL/min/1.73 m² for blacks and 104 ± 17 mL/min/1.73 m² for whites at baseline. For both blacks and whites, eGFRcys decline was minimal at younger ages (<35 years) and eGFRcys loss accelerated at older ages. However, acceleration of eGFRcys decline occurred at earlier ages for blacks than whites. Blacks had somewhat faster annualized rates of decline compared with whites, but differences were attenuated after adjustment in period 1 (0.13 mL/min/1.73 m² per year faster; P = 0.2). In contrast, during period 2, blacks had significantly faster annualized rates of decline, even after adjustment (0.32 mL/min/1.73 m² per year faster; P = 0.003). The prevalence of rapid decline was significantly higher for blacks versus whites, with prevalence rate ratios of 1.31 (95% CI, 1.04-1.63) for period 1 and 1.24 (95% CI, 1.09-1.41) for period 2. Differences were attenuated after full adjustment: adjusted prevalence rate ratios were 1.20 (95% CI, 0.95-1.49) for period 1 and 1.10 (95% CI, 0.96-1.26) for period 2.
  
  
  CONCLUSIONS
  No measured GFR.
  
  
  CONCLUSIONS
  eGFRcys decline differs by race at early ages, with faster annualized rates of decline for blacks. Future studies are required to explain the observed differences.
authors.affiliation: University of California San Francisco, San Francisco, CA, USA. carmenalicia.peralta@ucsf.edu
authors.forename: Carmen A
authors.initials: CA
authors.lastname: Peralta
authors.forename: Eric
authors.initials: E
authors.lastname: Vittinghoff
authors.forename: Nisha
authors.initials: N
authors.lastname: Bansal
authors.forename: David
authors.initials: D
authors.lastname: Jacobs
authors.forename: Paul
authors.initials: P
authors.lastname: Muntner
authors.forename: Bryan
authors.initials: B
authors.lastname: Kestenbaum
authors.forename: Cora
authors.initials: C
authors.lastname: Lewis
authors.forename: David
authors.initials: D
authors.lastname: Siscovick
authors.forename: Holly
authors.initials: H
authors.lastname: Kramer
authors.forename: Michael
authors.initials: M
authors.lastname: Shlipak
authors.forename: Kirsten
authors.initials: K
authors.lastname: Bibbins-Domingo
mesh_terms: D000293:Adolescent; D000328:Adult; D001741:Black or African American; D000367:Age Factors; D003324:Coronary Artery Disease / Q000453:epidemiology / Q000503:physiopathology; D005260:Female; D005919:Glomerular Filtration Rate; D006801:Humans; D007668:Kidney / Q000503:physiopathology*; D008137:Longitudinal Studies; D008297:Male; D011446:Prospective Studies; D018570:Risk Assessment; D012307:Risk Factors; D044465:White People; D055815:Young Adult
keywords: Trajectories; decline; kidney; race