Minor impairment of oral iron absorption in non-diabetic new dialysis patients

Background: Iron absorption is impaired in end-stage renal disease (ESRD). ESRD duration and diabetes mellitus (DM) are prominent risk factors in ESRD patients, associated with multi-system complications involving the gastrointestinal tract. Therefore, we suggest that DM and ESRD duration contribute to iron absorption impairment in ESRD. Since we administer oral iron during hemodialysis (HD) sessions, we assessed the relationship of DM and ESRD duration to intradialytic iron absorption. Methods: A 4-hr intradialytic oral iron absorption test was performed in 22 non-diabetic patients and 21 diabetic chronic HD patients. Elemental iron, 100 mg (iron(III)-hydroxide-polymaltose) was administered at dialysis start. Serum iron levels were measured hourly since iron ingestion, and standardized according to transferrin levels to correct for intradialytic blood volume changes. The primary end point was peak increase in standardized serum iron level (ΔI). ESRD duration and DM were defined as months on dialysis and the presence of DM before dialysis initiation, respectively. Evaluated confounding factors included age, gender, dry weight (DW), ultrafiltration volume (UF), UF /DW, eKt/V, transferrin saturation (%SAT), ferritin, parathyroid hormone (PTH), C-reactive protein (CRP) and erythropoietin (EPO) dosage. Results: ΔI was significantly inversely correlated with ESRD duration. DM was significantly associated with lower ΔI after statistically controlling for ESRD duration. These relationships remained significant after statistically controlling for %SAT, UF and UF/DW. %SAT was significantly inversely correlated with ΔI, but contributed to lower variability of ΔI (11%) than DM (15.2%) and ESRD duration (16.5%). Conclusions: Intradialytic iron absorption was less impaired in non-diabteic patients with shorter ESRD duration. Therefore, intradialytic oral iron therapy could be successful in these patients.