ORAL IRON-ABSORPTION TEST IN PATIENTS ON CAPD - COMPARISON OF FERROUSSULFATE AND A POLYSACCHARIDE FERRIC COMPLEX

We prospectively compared the absorption of ferrous sulfate to that of a polysaccharide ferric complex (Niferex(R)) in 5 healthy controls an d 7 stable patients on continuous ambulatory peritoneal dialysis (CAPD ). All study subjects received an equivalent of 150 mg of elemental ir on of either preparation, in a random fashion. After a baseline fastin g serum iron level was obtained, the serum iron concentration was meas ured at 2 h in the control group and at 2 and 4 h in the CAPD patients . One to 2 months later, all study subjects received the alternative i ron compound and were studied in an identical manner. A significant ri se in serum iron was only observed in the healthy subjects after the i ngestion of ferrous sulfate and not Niferex (ferrous sulfate 102 +/- ( SE) 9 vs. 142 +/- 7 Mg/dl, p = 0.0005; Niferex 96 +/- (SE) 10 vs. 102 +/- 12 mg/dl; baseline vs. 2 h, respectively). The absorption of both compounds was poor in the patients on CAPD, with the 2- and 4-hour ser um iron levels not significantly higher than the baseline values (ferr ous sulfate 73 +/- 7 vs. 107 +/- 21 vs. 109 +/- 21 mg/dl, p = NS; Nife rex 57 +/- 11 vs. 65 +/- 14 vs. 60 +/- 11 mg/dl, p = NS; baseline vs. 2 vs. 4 h, respectively). Our data suggest that the absorption of both ferrous sulfate and ferric polysaccharide complex is poor in patients on CAPD.