Oral or low-dose intravenous (IV) iron supplementation is linked with lower risks of premature death in non-dialysis, stage 5 chronic kidney disease (CKD) patients receiving erythropoiesis-stimulating agents (ESAs), a new Taiwanese study finds.
Der-Cherng Tarng, MD, of Taipei Veterans General Hospital and his team compared outcomes for iron supplement users and non-users among 31,971 CKD patients treated with ESAs (for serum creatinine greater than 6 mg/dL and hematocrit below 28%). Patient records were obtained from Taiwan’s National Health Insurance Research Database, which reflects a population of 23 million people.
Patients who received iron supplementation (oral and/or IV) had a 15% lower risk of all-cause mortality compared with non-users, according to results published in Nephrology Dialysis Transplantation (2015;30:1518-1525). The benefit extended for most iron dosages, except for monthly IV iron dosage greater than 200 mg. Although iron users were younger and more likely to receive nephrology care, the investigators believe these factors had minimal influence.
Patients who received iron also had a 3% lower risk of hospitalizations, although this came with a 5% higher risk of faster progression to end-stage renal disease (ESRD) requiring dialysis. Survivors had longer exposure to factors leading to ESRD.
Iron usage poses potential problems too. The route of iron administration remains controversial. Parenteral iron shows some nephrotoxicity, in addition to inducing intracellular iron buildup, lipid peroxidation, and cell injury, the investigators explained. “Accordingly, we recommend that oral route administration is an alternate option for iron supplementation in CKD 5 [non-dialysis] patients on account of the safety and convenience in outpatient practice,” they suggested.
Current guidelines do not provide recommendations for optimal iron routes, and oral iron is more convenient than IV iron.
As the study was observational, the findings need to be validated by randomized trials.