Iron Status and Survival in Diabetic Patients With Coronary Artery Disease

  1. Ewa A. Jankowska, MD, PHD, FESC3,8
  1. 1Department of Physiology, Wroclaw Medical University, Wroclaw, Poland
  2. 2Department of Genetics, Wroclaw University of Environmental and Life Sciences, Wroclaw, Poland
  3. 3Department of Heart Diseases, Wroclaw Medical University, Wroclaw, Poland
  4. 4Department of Cardiology, Centre for Heart Diseases, Military Hospital, Wroclaw, Poland
  5. 5Division of Applied Cachexia Research, Department of Cardiology, Charité Medical School, Berlin, Germany
  6. 6Centre for Stroke Research Berlin, Charité Medical School, Berlin, Germany
  7. 7Department of Cardiology, Hull York Medical School, University of Hull, Castle Hill Hospital, Kingston upon Hull, U.K.
  8. 8Laboratory for Applied Research on Cardiovascular System, Department of Heart Diseases, Wroclaw Medical University, Wroclaw, Poland
  1. Corresponding author: Ewa A. Jankowska, ewa.jankowska{at}umed.wroc.pl.

Abstract

OBJECTIVE To investigate the impact of iron status on survival in patients with type 2 diabetes and coronary artery disease (CAD).

RESEARCH DESIGN AND METHODS Serum ferritin, transferrin saturation (Tsat), and soluble transferrin receptor (sTfR) were measured in 287 patients with type 2 diabetes and stable CAD (65 ± 9 years of age, 78% men).

RESULTS During a mean follow-up of 45 ± 19 months, there were 59 (21%) deaths and 60 (21%) cardiovascular hospitalizations. Both serum ferritin and sTfR strongly predicted 5-year all-cause mortality rates, independently of other variables (including hemoglobin, measures of renal function, inflammation, and neurohormonal activation). There was an exponential relationship between sTfR and mortality (adjusted hazard ratio [HR] per 1 log mg/L: 4.24 [95% CI 1.43–12.58], P = 0.01), whereas the relationship between ferritin and mortality was U shaped (for the lowest and the highest quintiles vs. the middle quintile [reference group], respectively: adjusted HR 7.18 [95% CI 2.03–25.46], P = 0.002, and adjusted HR 5.12 [1.48–17.73], P = 0.01). Similar patterns were observed for the composite outcome of all-cause mortality or cardiovascular hospitalization, and in these multivariable models, low Tsat was related to unfavorable outcome.

CONCLUSIONS Both low and high serum ferritin (possibly reflecting depleted and excessive iron stores, respectively) along with high serum sTfR (reflecting reduced metabolically available iron) identify patients with type 2 diabetes and CAD who have a poor prognosis.

  • Received March 2, 2013.
  • Accepted July 7, 2013.

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This Article

  1. Diabetes Care
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