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Abstract: PO0476

Association Between Serum Indices of Iron Metabolism and Cardiovascular Morbidity in Patients with Pre-Dialysis CKD

Session Information

Category: Anemia and Iron Metabolism

  • 200 Anemia and Iron Metabolism

Authors

  • Hasegawa, Takeshi, Showa Daigaku, Shinagawa-ku, Tokyo, Japan
  • Imaizumi, Takahiro, Nagoya Daigaku Daigakuin Igakukei Kenkyuka Igakubu, Nagoya, Aichi, Japan
  • Murotani, Kenta, Kurume Daigaku, Kurume, Fukuoka, Japan
  • Hamano, Takayuki, Nagoya Shiritsu Daigaku Daigakuin Igaku Kenkyuka Igakubu, Nagoya, Aichi, Japan
  • Komaba, Hirotaka, Tokai Daigaku Igakubu Daigakuin Igaku Kenkyuka, Isehara, Kanagawa, Japan
  • Fujii, Naohiko, Hyogo Kenritsu Nishinomiya Byoin, Nishinomiya, Hyogo, Japan
  • Fukagawa, Masafumi, Tokai Daigaku Igakubu Daigakuin Igaku Kenkyuka, Isehara, Kanagawa, Japan
Background

The optimal ranges of serum iron markers are uncertain in predialysis chronic kidney disease (CKD) patients. Therefore, we aimed to investigate the association between serum indices of iron metabolism and the incidence of CVD events in patients with predialysis CKD using the CKD-Japan Cohort (CKD-JAC) data.

Methods

We prospectively followed 1,550 CKD patients aged 20-75 years with an estimated glomerular filtration rate (eGFR) <60 mL/min/1.73 m2 for a mean of 4.21 years. We set serum transferrin saturation (TSAT) and ferritin levels as the main exposures to be tested. Our main outcome measures were any of the CVD events including congestive heart failure (CHF) identified at each facility and adjudicated by the independent cardiac function evaluation committee. Multivariable Cox proportional hazards regression models were employed to examine the association between serum TSAT or ferritin levels with time to events. All models were stratified by facilities and adjusted for potential confounders. We also applied the multivariable fractional polynomial interaction (MFPI) approach to investigate whether serum TSAT or ferritin levels are the effect modifier of the association between iron supplementation and the outcomes.

Results

In the overall cohort, 208 (13.4 %) patients developed CVD events (including 97 CHF) during the follow-up period (26.6 events/1000 person-year). The incidence rate of CVD events was the highest in the TSAT < 20% category (33.0 events/1000 person-year). Compared to patients in the TSAT > 40% category, those in the TSAT < 20% category demonstrated an increased risk of CVD events (adjusted hazard ratio (AHR): 1.86, 95% confidence interval (CI): 1.06-3.26) and CHF events (AHR: 2.82, 95% CI: 1.15-6.89), respectively. There was no association between serum ferritin levels and the risk of CVD or CHF events. MFPI analyses showed a reduced risk of CVD in patients receiving iron supplementation only in patients with TSAT < 20% (P for interaction=0.02).

Conclusion

Maintaining TSAT > 20% could be effective to reduce the risk of developing CVD events (especially CHF) in patients with predialysis CKD. Our analyses also suggest that iron-deficient patients with predialysis CKD may benefit from iron supplementation for reduced risk of CVD events.