WASHINGTON—Functional iron deficiency anemia (IDA) in patients with chronic kidney disease (CKD) is associated with an increased risk for death and cardiovascular-related hospitalization, according to study findings presented at the American Society of Nephrology’s Kidney Week 2019 meeting. Absolute IDA is associated with an elevated risk of hospitalization.

A team at Baylor College of Medicine in Houston led by Sankar D. Navaneethan, MD, studied 933,463 Veterans Administration patients with non-dialysis-dependent CKD, of whom 191,719 (20.6%) had anemia. Of these patients, 45,260 (23.6%) had both transferrin saturation (TSAT) and ferritin level measured. In this group, 13,684 patients (30%) and 7917 (17.5%) had functional IDA.

Dr Navaneethan and his colleagues defined functional IDA as a transferrin saturation (TSAT) less than 20% and ferritin level of 100 to 800 ng/mL and absolute IDA as a TSAT less than 20% and ferritin level less than 100 ng/mL. A total of 31,635 patients died during a median follow-up period of 3.9 years, and 6117 patients progressed to end-stage renal disease during a median follow-up period of 3.6 years. Compared with patients who did not have anemia, those with anemia had a significant 58% increased risk for death and 72% increased risk for transitioning to dialysis.

In addition, compared with patients who did not have iron deficiency, those with functional IDA had a significant 11% higher risk for death and a 21% and 13% higher risk of 1- and 2-year cardiovascular (CV)-related hospitalization, respectively. The functional IDA group was not at increased risk for dialysis. Patients with absolute IDA had significant 20% and 11% higher risks of 1- and 2-year CV hospitalization, respectively, but they were not at increased risk for death or dialysis.

In addition, patients with a ferritin level above 500 ng/mL had a significant 38% increased risk for death compared with patients who did not have iron deficiency.

The investigators also reported their study findings in Nephrology Dialysis Transplantation.

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Reference

Awan AA, Walter CP, Richardson PA, et al. Prevalence, correlates and outcomes of absolute and functional iron deficiency anemia in non-dialysis-dependent chronic kidney disease. Presented at the American Society of Nephrology’s Kidney Week 2019 meeting held November 5 to 10 in Washington, DC. Poster SA-PO239.