BackgroundHemodialysis (HD) patients with functional iron deficiency often develop resistance to recombinant human erythropoietin (rhEPO). Recent studies have shown that intravenous ascorbic acid (IVAA) administration could override rhEPO resistance in HD patients. This study was undertaken to test the effects of IVAA in HD patients with normoferritinemic functional iron deficiency accompanied by EPO-hyporesponsive anemia.MethodsFifty-eight HD patients with normoferritinemic anemia (between 100 and 500 μg/L) were included and divided into the control (N=25) and IVAA (N=33) groups. IVAA patients received 500 mg of IVAA with each dialysis session for 3 months and an additional 4-month follow-up after the end of the therapy.ResultsTwenty patients had a response to IVAA with a significant increase in hemoglobin level (Hgb>1.0 g/dL) and reduction of weekly rhEPO dosage compared with the control group after 3 months of treatment (P<0.05). Compared with non-responders, transferrin saturation (TSAT) was significantly decreased in the responders group (26±11 vs. 35±14%, P<0.05) on baseline data. There was a significant increase in serum iron and TSAT (baseline vs. 3 months, serum iron 57±22 vs. 108±22 μg/dL, TSAT 26±11 vs. 52±7%, P<0.05) and a decrease in serum ferritin (377±146 vs. 233±145 ng/mL, P<0.05) in the responders group (N=20), but no significant changes in the control and non-responders groups (N=13) at 3-month treatment.ConclusionIVAA can be a potent and effective adjuvant therapy for HD patients with rhEPO-resistant normoferritinemic anemia. In addition, IVAA can reduce the dosage of rhEPO for anemia correction.

This study inquired the relationship between serum N-terminal pro-brain natriuretic peptide (NT-proBNP) levels and left ventricular (LV) dysfunction and extracellular water in continuous ambulatory peritoneal dialysis (CAPD) patients. We conducted a cross-sectional study of 30 CAPD patients. Each patient was admitted to the department of internal medicine, Chosun University Hospital between February and October, 2006. Echocardiography was performed using HDI 5000, allowing M-mode, two-dimensional measurement. A multifrequency bioimpedance analyzer was used; extracellular water was calculated as a percentage of total body water and was understood as the index of volume load of CAPD patients. The mean age was 47±12 years. Underlying causes of renal failure were 14 with diabetes mellitus, 7 with hypertension, and 9 with chronic glomerulonephritis. The mean serum NT-proBNP level was 14236.56 (83-35,000) pg/mL. LV mass index and LV ejection fraction were 151.67±42.5 g/m2 and 57.48±12.9%, respectively. The mean extracellular water was 35.97±1.04%. Serum NT-proBNP levels correlated positively with LV mass index (r=0.768, p=0.01) and extracellular water (r=0.866, p=0.01) and negatively with LV ejection fraction (r=-0.808, p=0.01). Serum NT-proBNP levels significantly correlated with LV mass index, LV ejection fraction, and extracellular water. Therefore, serum NT-proBNP levels can be a clinical predictive marker for LV hypertrophy, LV dysfunction, and volume status in CAPD patients.