title: Longitudinal trends in serum ferritin levels and associated factors in a national incident hemodialysis cohort.
abstract: The rise in serum ferritin levels among US maintenance hemodialysis patients has been attributed to higher intravenous iron administration and other changes in practice. We examined ferritin trends over time in hemodialysis patients and whether iron utilization patterns and other factors [erythropoietin-stimulating agent (ESA) prescribing patterns, inflammatory markers] were associated with ferritin trajectory.
  
  
  
  In a 5-year (January 2007–December 2011) cohort of 81 864 incident US hemodialysis patients, we examined changes in ferritin averaged over 3-month intervals using linear mixed effects models adjusted for intravenous iron dose, malnutrition and inflammatory markers. We then examined ferritin trends across strata of baseline ferritin level, dialysis initiation year, cumulative iron and ESA use in the first dialysis year and baseline hemoglobin level.
  
  
  
  In models adjusted for iron dose, malnutrition and inflammation, mean ferritin levels increased over time in the overall cohort and across the three lower baseline ferritin strata. Among patients initiating dialysis in 2007, mean ferritin levels increased sharply in the first versus second year of dialysis and again abruptly increased in the fifth year independent of iron dose, malnutrition and inflammatory markers; similar trends were observed among patients who initiated dialysis in 2008 and 2009. In analyses stratified by cumulative iron use, mean ferritin increased among groups receiving iron, but decreased in the no iron group. In analyses stratified by cumulative ESA dose and baseline hemoglobin, mean ferritin increased over time.
  
  
  
  While ferritin trends correlated with patterns of iron use, increases in ferritin over time persisted independent of intravenous iron and ESA exposure, malnutrition and inflammation.
authors.affiliation: Harold Simmons Center for Kidney Disease Research and Epidemiology, University of California, Irvine, School of Medicine, CA, USA.|Department of Medicine, Inje University, Busan, South Korea.
authors.forename: Taehee
authors.initials: T
authors.lastname: Kim
authors.affiliation: Harold Simmons Center for Kidney Disease Research and Epidemiology, University of California, Irvine, School of Medicine, CA, USA.
authors.forename: Connie M
authors.initials: CM
authors.lastname: Rhee
authors.affiliation: Harold Simmons Center for Kidney Disease Research and Epidemiology, University of California, Irvine, School of Medicine, CA, USA.
authors.forename: Elani
authors.initials: E
authors.lastname: Streja
authors.affiliation: Harold Simmons Center for Kidney Disease Research and Epidemiology, University of California, Irvine, School of Medicine, CA, USA.
authors.forename: Yoshitsugu
authors.initials: Y
authors.lastname: Obi
authors.affiliation: Harold Simmons Center for Kidney Disease Research and Epidemiology, University of California, Irvine, School of Medicine, CA, USA.
authors.forename: Steven M
authors.initials: SM
authors.lastname: Brunelli
authors.affiliation: Nephrology Section, Memphis Veterans Affairs Medical Center, Memphis, TN, USA.|Division of Nephrology, University of Tennessee Health Science Center, Memphis, TN, USA.
authors.forename: Csaba P
authors.initials: CP
authors.lastname: Kovesdy
authors.affiliation: Harold Simmons Center for Kidney Disease Research and Epidemiology, University of California, Irvine, School of Medicine, CA, USA.|Department of Medicine, Veterans Affairs Long Beach Health Care System, Long Beach, CA, USA.
authors.forename: Kamyar
authors.initials: K
authors.lastname: Kalantar-Zadeh
mesh_terms: D061605:Administration, Intravenous; D000368:Aged; D015415:Biomarkers / Q000097:blood*; D004921:Erythropoietin / Q000008:administration & dosage; D005260:Female; D005293:Ferritins / Q000097:blood*; D006454:Hemoglobins / Q000378:metabolism; D006801:Humans; D007249:Inflammation / Q000097:blood / Q000503:physiopathology*; D007501:Iron / Q000008:administration & dosage*; D007676:Kidney Failure, Chronic / Q000097:blood / Q000150:complications* / Q000628:therapy; D008137:Longitudinal Studies; D008297:Male; D044342:Malnutrition / Q000097:blood / Q000503:physiopathology*; D008875:Middle Aged; D006435:Renal Dialysis
chemical_list: D015415:Biomarkers; D006454:Hemoglobins; D004921:Erythropoietin; D005293:Ferritins; D007501:Iron
keywords: ferritin; hemodialysis; iron; longitudinal trends