title: GDF-15, iron, and inflammation in early chronic kidney disease among elderly patients.
abstract: OBJECTIVE
  The aim of the study was to assess GDF-15 and iron status in patients in early stages of chronic kidney disease with a particular emphasis on elderly population in association of classic iron status parameters with novel iron homeostasis biomarkers and inflammatory parameters.
  
  
  METHODS
  Serum concentrations of GDF-15, iron (Fe), transferrin saturation, soluble transferrin receptor (sTfR), hepcidin, high-sensitive C-reactive protein (hsCRP), interleukin 6 (IL-6), and hemoglobin were measured in 56 patients ≥65 years of age and in 31 <65 years of age.
  
  
  RESULTS
  In patients ≥65 years, serum concentrations of GDF-15 and hsCRP were significantly higher in comparison with younger group. There was no statistically significant difference in hemoglobin, iron, hepcidin, and sTfR concentration between the two studied groups. In both groups GDF-15 was significantly correlated with hemoglobin, eGFR, hsCRP, and IL-6. GDF-15 was significantly higher in patients with anemia in comparison with their non-anemic counterparts. In multivariate analysis, hemoglobin was found to be a predictor of log GDF-15 (beta value = 0.36, P = 0.006, R (2) = 37 %).
  
  
  CONCLUSIONS
  An intricate interplay between renal function, anemia, and GDF-15 concentrations awaits further studies, as there are few data regarding pathophysiological role of GDF-15 in diabetes, kidney disease, and other comorbidities. Further understanding regarding the signaling pathways of GDF-15 may help to discover next pieces in the exciting puzzle of GDF-15. Finally, as studies dealing with normal level of GDF-15 in the healthy aged are lacking, it is possible that the higher values of GDF-15 values found in the present study represent values of GDF-15 according to age more than CKD levels.
authors.affiliation: 2nd Department of Nephrology and Hypertension with Dialysis Unit, Medical University of Bialystok, Marii Skłodowskiej - Curie 24a, 15-276, Białystok, Poland.
authors.forename: Ewelina
authors.initials: E
authors.lastname: Lukaszyk
authors.affiliation: Department of Allergy and Internal Medicine, Medical University of Bialystok, Bialystok, Poland.
authors.forename: Mateusz
authors.initials: M
authors.lastname: Lukaszyk
authors.affiliation: 2nd Department of Nephrology and Hypertension with Dialysis Unit, Medical University of Bialystok, Marii Skłodowskiej - Curie 24a, 15-276, Białystok, Poland.
authors.forename: Ewa
authors.initials: E
authors.lastname: Koc-Zorawska
authors.affiliation: Department of Allergy and Internal Medicine, Medical University of Bialystok, Bialystok, Poland.
authors.forename: Anna
authors.initials: A
authors.lastname: Bodzenta-Lukaszyk
authors.affiliation: 2nd Department of Nephrology and Hypertension with Dialysis Unit, Medical University of Bialystok, Marii Skłodowskiej - Curie 24a, 15-276, Białystok, Poland. jolmal@poczta.onet.pl.
authors.forename: Jolanta
authors.initials: J
authors.lastname: Malyszko
mesh_terms: D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D015415:Biomarkers / Q000097:blood; D002097:C-Reactive Protein / Q000378:metabolism; D016022:Case-Control Studies; D005260:Female; D055436:Growth Differentiation Factor 15 / Q000097:blood*; D006454:Hemoglobins / Q000378:metabolism; D064451:Hepcidins / Q000097:blood; D006801:Humans; D007249:Inflammation; D015850:Interleukin-6 / Q000097:blood; D007501:Iron / Q000097:blood*; D008297:Male; D008875:Middle Aged; D011990:Receptors, Transferrin / Q000097:blood; D051436:Renal Insufficiency, Chronic / Q000097:blood* / Q000150:complications*; D061250:Transferrins / Q000097:blood
chemical_list: D015415:Biomarkers; C526140:GDF15 protein, human; D055436:Growth Differentiation Factor 15; D006454:Hemoglobins; D064451:Hepcidins; C508600:IL6 protein, human; D015850:Interleukin-6; D011990:Receptors, Transferrin; D061250:Transferrins; D002097:C-Reactive Protein; D007501:Iron
keywords: Chronic kidney disease; GDF-15; Hepcidin; Inflammation; Iron