Lipocalin-2, Soluble Transferrin Receptor, and Erythropoietin in Anemia During Mild Renal Dysfunction

BACKGROUND: Mild renal dysfunction (MRD) is a common condition often associated with diabetes or inflammation and regarded as a risk factor for cardiovascular disease in patients with hypertension. Few studies have examined the role of lipocalin-2 (LCN2) as a regulator of iron and a contributor to anemia in MRD. The aim of this study was to investigate the relationship between LCN2, soluble transferrin receptor (sTfR), erythropoietin (EPO), reticulocyte production, and the prevalence of anemia in MRD. METHODS: A total of 235 subjects with MRD were evaluated. LCN2, sTfR, EPO, and iron levels were measured. Reticulocyte maturity index (RMI) and corrected LCN2 (cLCN2) values were calculated using reticulocyte subpopulations and the inflammation index, respectively. RESULTS: Subjects with LCN2 elevation had significantly higher sTfR and significantly lower RMI levels than those without LCN2 elevation. Compared to subjects without LCN2 elevation, those with LCN2 elevation exhibited significantly lower hemoglobin (12.9 ± 1.6 g/dL vs 14.0 ± 1.7 g/dL, p < 0.001) and more prevalent anemia (27.7% vs 13.3%, p = 0.008). Patients with anemia had significantly higher LCN2 and cLCN2 than those without anemia. LCN2 was positively correlated with sTfR and negatively correlated with RMI but not EPO. Elevated LCN2 led to a 1.3-fold increase in the prevalence of anemia (odds ratio: 1.302; 95% CI: 1.012–2.527; p < 0.001). CONCLUSION: LCN2 elevation may contribute to the development of anemia in MRD, particularly in conjunction with restricted iron availability and suppressed reticulocyte production.