Evaluation value of iron metabolism disorders in sepsis patients in an intensive care unit / 中华急诊医学杂志

ABSTRACT

Objective:To evaluate iron metabolism disorders in sepsis patients and explore the effect of iron deficiency on mortality.Methods:Patients ( n=130) who were admitted to the emergency intensive care unit (ICU) of the First Affiliated Hospital of Dalian Medical University from September 2016 to July 2018 and met the diagnostic criteria of Sepsis 3.0 were selected, and sex- and age-matched healthy volunteers ( n=20) were enrolled as a control group. Peripheral venous blood samples were collected in sepsis patients on day 1, 3 and 7 after admission, or in the healthy volunteers upon enrollment, to detect iron metabolism-related indicators and interleukin-6 (IL-6); the Sequential Organ Failure Assessment (SOFA) score was calculated upon hospital admission. Iron metabolism-related indicators were compared between the groups; the correlation of plasma iron with hemoglobin, hepcidin, ferritin, IL-6, sTFR/log ferritin and the ability of plasma iron to predict 28-day death of sepsis patients were analyzed. Results:Sepsis patients developed significant anemia on day 3 after admission; plasma iron, transferrin, iron saturation, total iron binding capacity and unsaturated iron binding capacity in the first week of admission were significantly lower than those in the control group; distribution width of red blood cells, ferritin, IL-6, hepcidin and soluble transferrin receptor were significantly higher than those in the control group. Distribution width of red blood cells, ferritin and hepcidin on day 3 and 7 after admission, and plasma iron and iron saturation on day 7 after admission were significantly higher than those on day 1. However, total iron binding capacity and unsaturated iron binding power on day 7, and sTFR/log ferritin on day 3 were significantly lower than those on day 1. Patients in the survival and non-survivor groups in the first week of admission had significant anemia on day 3 and 7, but the anemia was worse in the non-survivor group. Transferrin, total iron binding capacity, and unsaturated iron binding capacity in the non-survivor group in the first week of admission, and plasma iron in the non-survivor group on day 3 and 7, were significantly lower than those in the survival group. Ferritin, IL-6 and hepcidin in the non-survivor group in the first week of admission, and iron saturation on day 7 were significantly higher than those in the survival group. Spearman correlation analysis showed that plasma iron was negatively correlated with IL-6 ( r=-0.391, P<0.01), ferritin ( r=-0.293, P=0.001) and hepcidin ( r=-0.209, P=0.017), but not with hemoglobin ( r=0.005, P=0.958). The area under the operation curve (AUC) for plasma iron for predicting 28-day mortality in sepsis patients was 0.524 (95% CI 0.416-0.631, P=0.656). Conclusions:Sepsis patients have significant anemia and iron metabolism disorders in the early stage, while non-survival patients are more severe. Reduced plasma iron level has no capacity to predict 28-day mortality of sepsis patients. In addition, decreased plasma iron level is not related to decreased hemoglobin, and thus iron supplementation should be cautious in sepsis patients.