Elevated Neutrophil Gelatinase Lipocalin Levels Are Associated With Increased Oxidative Stress in Hemodialysis Patients

BACKGROUND: Administration of intravenous iron is an essential treatment of anemia in hemodialysis patients, but it may lead to oxidative stress and increased morbidity and mortality. There is evidence that neutrophil gelatinase-associated lipocalin (NGAL) is protective against oxidative stress and thus the aim of the present study was to investigate the relationship between plasma NGAL and advanced oxidative protein products (AOPP) in hemodialysis patients treated with intravenous iron. METHODS: In a prospective study, 47 hemodialysis patients (mean age 63 years, SD = 13.6; 40% women) were enrolled from two separate hospitals. Oxidative stress was induced by an intravenous administration of 100 mg iron saccharate 0.5 h after the start of dialysis. Blood samples were drawn at the beginning of the dialysis, 0.5 h after iron administration and at the end of dialysis. NGAL levels were measured from the first blood sample, AOPP levels were measured from all blood samples. RESULTS: Our results showed that higher NGAL and AOPP levels at the beginning of the dialysis, prior to iron administration, significantly predicted higher levels of AOPP toward the end of dialysis, (β = 0.355, SE = 0.054, P = 0.035; β = 0.297, SE = 0.159, P = 0.043, respectively). CONCLUSIONS: Our results suggest that higher level of NGAL is a risk factor for oxidative stress, as measured by AOPP levels, in dialysis patients receiving intravenous iron. Our findings could identify dialysis patients who are at higher risk from iron supplementation via measurement of NGAL levels.