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.
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.