Antiplatelet therapy alters iron requirements in hemodialysis patients

Hemodialysis(HD) patients are prone to develop iron deficiency because of c onsumption of iron stores during erythropoietin (EPO) therapy. Data are nee ded to establish the factors involved in the different iron needs among the se patients. Sixty-five HD patients were prospectively studied during a yea r. The subjects were dialyzed through polytetrafluoroethylene (PTFE) grafts (n = 23), arteriovenous native fistulae (n = 41), and a Permcath (n = 1). Twenty-four patients were administered aspirin; 23 patients, ticlopidine; 1 patient, dipyridamole; and 4 patients, anticoagulation with acenocoumarol. Iron supplementation (oral or parenteral) and laboratory parameters were r ecorded monthly. Significant differences In iron requirements, depending on the use of antiplatelet and/or anticoagulation agents, were found. Total p arenteral iron supplements were greater in patients on antiplatelet therapy with either native or graft vascular accesses compared with the rest (2,40 6 +/- 1,445 versus 1,562 +/- 858 mg; P = 0.0081). Twelve of 52 patients on antiplatelet therapy required oral Iron and only 1 of 13 patients not on an tiplatelet therapy was administered oral iron supplements (P < 0.05). Patie nts on antiplatelet therapy were administered more transfusions (1.9 +/- 3. 8 transfusions/y) than individuals not on antiplatelet therapy (0.15 +/- 0. 3 transfusions/y; P = 0.0015). However, only patients with PTFE grafts on a ntiplatelet therapy had a post-HD bleeding time longer than patients not on antiplatelet therapy (9.1 +/- 3.6 versus 5.7 +/- 3.9 minutes; P < 0.0001). Multiple logistic regression analysis showed that the use of antiplatelet agents (P < 0.05) is an independent factor that increased the probability o f requiring greater parenteral Iron supplements (>2.5 g/y). Patients with P TFE grafts required more EPO than those with autologous fistulae (160 +/- 9 3 versus 100 +/- 63 U/kg/wk; P = 0.012). No differences between groups were found that could explain this finding. Antiplatelet and/or anticoagulation therapy implied the use of greater amounts of iron supplements in HD patie nts. Although these greater requirements of iron occurred in parallel with bleeding from the vascular access, additional data favor the existence of o ther factors, eg, interdialytic blood losses. The present study suggests th at antiplatelet therapy may be an important factor in determining iron requ irements in HD patients. Moreover, our data relate for the first time the u se of prosthetic grafts with increased EPO requirements, an issue of great potential importance in the debate about vascular access policy in dialysis units. (C) 2000 by the National Kidney Foundation, Inc.