Iron Absorption in Patients with Chronic Uremia on Maintenance Hemodialysis and in Healthy Volunteers Measured with a Simple Oral Iron Load Test

Abstract

Gastrointestinal iron absorption was measured by an oral iron load test in patients with uremia on maintenance hemodialysis (n = 19), with iron overload (n = 9), iron deficiency (n = 10) and in healthy volunteers (n = 9). After an overnight fast, serum iron was measured before, and 1, 2, 4 and 6 h after administration of 100 mg ferrous chloride. Bone marrow iron was assessed after staining with Prussian blue. The study shows that iron absorption is impaired in uremic patients. Even uremic subjects with iron deficiency absorbed significantly less than normal subjects. Patients with iron overload and uremia absorbed even less, showing that the iron status of the patient influences absorption also in uremia.

Parenteral Iron: Pharmacology and Clinical Use

“…There are conflicting reports on the extent of oral iron absorption in patients with renal failure receiving erythropoietin, ranging from poor [31]to excellent [32]. Goch et al [31], for example, in a single-center study, showed that uremic subjects with iron deficiency absorbed significantly less oral iron than did subjects with normal renal function and iron deficiency.…”

“…Goch et al [31], for example, in a single-center study, showed that uremic subjects with iron deficiency absorbed significantly less oral iron than did subjects with normal renal function and iron deficiency.…”

Correction of Uremic Iron Deficiency Anemia in Hemodialyzed Patients: A Prospective Study

“…The main controversy at present is what is the most effective route to prescribe supplemental iron: oral [14, 15, 16, 17, 18] or parenteral [2, 4, 12, 18, 19, 20, 21, 22, 23]. This derives from conflicting reported observations of intestinal iron absorption in chronic uremic subjects that ranged from unimpaired [24, 25, 26, 27] to substantially reduced [28, 29, 30, 31]. These differences can be explained by the normal large variability in absorption between subjects or in subjects on repeated testing, variable test dosages, use of ferric or ferrous markers, as well as by highly skewed distribution of data [32].…”

“…This number is well beyond the number of cases included in every published study dealing with the problem of intestinal iron absorption in chronic uremics. Besides, the methods applied to evaluate iron absorption in patients affected by chronic renal failure have also been heterogeneous: fecal collection [14], iron red cell utilization [25], whole-body counting [26, 27, 28], the double isotope technique [24], or an oral iron load test [31]. …”

Anemia during the Predialysis Period: A Key to Cardiac Damage in Renal Failure

“…In a recent Dutch study [63], only 1% of the patients using EPO on peritoneal dialysis and only 19% using EPO on hemodialysis were receiving intravenous iron, whereas the majority of these patients were receiving oral iron. Oral iron, however, is poorly absorbed in chronic renal failure [64, 65, 66]and is much less effective than the intravenously administered form in hemodialysis [57, 58]or in peritoneal dialysis [67, 68]patients. Perhaps these physicians fear the side effects of intravenous iron.…”