Intravenous iron therapy and risk for progressive loss of kidney function in patients with chronic kidney disease.

Background: Intravenous (IV) iron is used in the treatment of anemia in patients with chronic kidney disease (CKD). Several lines of evidence have brought up potential concerns regarding the effect of IV iron on the kidney, specifically the possibility of IV iron leading to renal injury and hastening the progression of CKD.

Methods: We performed a retrospective analysis of 77 patients to assess the rate of change in kidney function prior to and after IV iron infusion.

Results: Patients were followed for an average of 21.3 months (range 2-35) prior and 32.8 months (range 2-58) after the single iron infusion. Sixty-one percent of patients had CKD stage 3 and 30% were at CKD stage IV at the time of iron infusion. Of the 77 patients, 74.1% received iron dextran and 25.9% received ferric gluconate (1 g total). The average slope before and after iron infusion for 1/serum creatinine versus time (months) were -0.0066 and -0.0053, respectively (p = 0.12). The average slope before and after iron infusion for glomerular filtration rate versus time (months) were -0.5439 and -0.2998, respectively (p = 0.14). There was no difference in subgroup analysis in the rate of change in renal function in those with more advanced renal function as opposed to those with more preserved renal function.

Conclusion: In this limited retrospective study, IV iron dextran or ferric gluconate was not associated with a change in the rate of progression of CKD.