ASN's Mission

ASN leads the fight to prevent, treat, and cure kidney diseases throughout the world by educating health professionals and scientists, advancing research and innovation, communicating new knowledge, and advocating for the highest quality care for patients.

learn more

Contact ASN

1401 H St, NW, Ste 900, Washington, DC 20005

email@asn-online.org

202-640-4660

The Latest on Twitter

Kidney Week

Abstract: PO0280

Lower Transferrin Saturation (TSAT) Index Is Associated with an Anemia-Independent Risk of Increased Mortality in Non-Dialysis (ND) CKD Patients

Session Information

Category: Anemia and Iron Metabolism

  • 200 Anemia and Iron Metabolism

Authors

  • Guedes, Murilo Henrique, Pontificia Universidade Catolica do Parana, Curitiba, PR, Brazil
  • Muenz, Daniel G., Arbor Research Collaborative for Health, Ann Arbor, Michigan, United States
  • Zee, Jarcy, Arbor Research Collaborative for Health, Ann Arbor, Michigan, United States
  • Bieber, Brian, Arbor Research Collaborative for Health, Ann Arbor, Michigan, United States
  • Wachter, Sandra, Vifor Pharma Ltd, Glattbrugg, Zurich, Switzerland
  • Stengel, Benedicte, Centre de Recherche en Epidemiologie et Sante des Populations, Villejuif, Île-de-France, France
  • Massy, Ziad, Centre de Recherche en Epidemiologie et Sante des Populations, Villejuif, France
  • Reichel, Helmut, Nephrological Center, Villingen-Schwenningen, Baden-Württemberg, Germany
  • Charytan, David M., NYU Langone Health, New York, New York, United States
  • Wong, Michelle M.Y., The University of British Columbia, Vancouver, British Columbia, Canada
  • Pisoni, Ronald L., Arbor Research Collaborative for Health, Ann Arbor, Michigan, United States
  • Robinson, Bruce M., Arbor Research Collaborative for Health, Ann Arbor, Michigan, United States
  • Pecoits-Filho, Roberto, Arbor Research Collaborative for Health, Ann Arbor, Michigan, United States
Background

Iron Deficiency (ID), defined by a TSAT index <20 %, is present in approximately half of ND-CKD patients, varying little by CKD stage. Distinct from approaches in conditions such as heart failure, the importance of iron reserves and the basis for iron therapy in CKD has focused primarily on supporting effective erythropoiesis. A comprehensive approach and design to estimate the impact of ID, independently from hemoglobin (Hb) levels, on mortality risk has not been explored in ND-CKD until the present.

Methods

5144 patients from Brazil (N=294), France (N=2227), the US (N=494), and Germany (N=2129) enrolled in the Chronic Kidney Disease Outcomes and Practice Patterns Study (CKDopps) from 2013-2019 with available TSAT were included in the analysis. We categorized patients by first available TSAT at enrollment. Hb measurements at same time as TSAT were used. Cox models were used to estimate hazard ratios (HR) of TSAT on mortality, censored at start of dialysis or kidney transplantation. Models were progressively adjusted for confounders, including demographics, comorbidities, inflammation surrogates, treatment with erythropoietin stimulating-agents and Hb.

Results

Sample characteristics were: 59% male; 45% diabetes; and mean (SD) age 69 (13) years, eGFR 28 (11) mL/min, Hb 12 (2) g/dL, TSAT 24 (2) %, ferritin 196 (214) ng/dL. TSAT levels below 25% were progressively associated with higher mortality risk, while patients with TSAT greater than 45% tended to have higher risks for mortality (Figure).

Conclusion

ID, as measured by the TSAT index, is associated with higher risk of all-cause mortality in ND-CKD patients, even after extensive adjustments for clinical, demographic and biochemical confounders, including Hb levels. Interventional studies evaluating the impact of iron supplementation and alternative targets on clinical outcomes in ND-CKD patients are needed to better inform ID management strategies.

Funding

  • Commercial Support