Intravenous iron increases labile serum iron but does not impair forearm blood flow reactivity in dialysis patients.

Randomized placebo-controlled study in stable adults with end-stage renal disease on peritoneal dialysis (CAPD or APD) at the Medical University Vienna. Nineteen participants were assigned to the iron sucrose arm.

A single 300 mg intravenous iron sucrose infusion (Venofer) was given over 2 hours in 50 mL 0.9% sodium chloride. The active regimen was compared with placebo infusion.

A single 300 mg intravenous iron sucrose infusion increased circulating labile iron markers and raised basal forearm blood flow, but it did not impair vascular reactivity. After iron, total iron, non-transferrin-bound iron, and redox-active iron increased, and basal forearm blood flow was 3.73 mL/min/100 mL versus 2.34 mL/min/100 mL after placebo (P < 0.05 vs baseline, P < 0.01 vs iron). However, responses to acetylcholine, GTN, and L-NMMA remained similar before and after iron, with no significant between-group difference in forearm blood flow reactivity (P = 0.08). The authors interpreted the rise in basal flow as possible iron-induced vasodilation and concluded that acute iron sucrose did not worsen endothelial or endothelium-independent vascular function.

Small single-arm sample and short-term, single-dose exposure limit inference about longer-term cardiovascular safety. Findings rely on surrogate vascular measures in stable peritoneal dialysis patients from one center, so generalizability is limited. Adverse events were reported in the iron group, but the study was not designed to assess clinical cardiovascular outcomes.