Iron deficiency diagnosed using hepcidin on critical care discharge is an independent risk factor for death and poor quality of life at one year: an observational prospective study on 1161 patients

Abstract

BackgroundIron deficiency is difficult to diagnose in critically ill patients, but may be frequent and may impair recovery. Measurement of hepcidin could help in the diagnosis of iron deficiency. We aim to assess if iron deficiency diagnosed using hepcidin is associated with poorer outcome one year after an intensive care unit stay.MethodsWe used the prospective FROG-ICU, multicentre (n = 28 ICUs), observational cohort study of critically ill survivors followed up one year after intensive care unit discharge. Iron deficiency was defined as hepcidin < 20 ng/l, ferritin < 100 ng/l or soluble transferrin receptor (sTfR)/log(ferritin) > 0.8, measured in blood drawn at intensive care unit discharge. Main outcomes were one-year all-cause mortality and poor quality of life (defined as a Short Form 36 (SF-36) score below the median).ResultsAmong the 2087 patients in the FROG-ICU cohort, 1570 were discharged alive and 1161 had a blood sample available at intensive care unit discharge and were included in the analysis. Using hepcidin, 429 (37%) patients had iron deficiency, compared to 72 (6%) using ferritin alone and 151 (13%) using the sTfR/log(ferritin) ratio. Iron deficiency diagnosed according to low hepcidin was an independent predictor of one-year mortality (OR 1.51 (1.10–2.08)) as was high sTfR/log ferritin ratio (OR = 1.95 (1.27–3.00)), but low ferritin was not. Severe ID, defined as hepcidin < 10 ng/l, was also an independent predictor of poor one-year physical recovery (1.58 (1.01–2.49)).ConclusionsIron deficiency, diagnosed using hepcidin, is very frequent at intensive care unit discharge and is associated with increased one-year mortality and poorer physical recovery. Whether iron treatment may improve these outcomes remains to be investigated.Electronic supplementary materialThe online version of this article (10.1186/s13054-018-2253-0) contains supplementary material, which is available to authorized users.

Using arterial-venous oxygen difference to guide red blood cell transfusion strategy

“…We did not systematically record A-V O 2diff and O 2 ER after transfusion and, therefore, cannot describe the A-V O 2diff and O 2 ER changes before and after RBC transfusion in the "appropriate" and "inappropriate" groups. In addition, although we showed a trend to an association of higher RDW values and mortality, as recently described [42], this was not confirmed in the multivariable analysis; nonetheless, there is a complex relationship between RDW values, iron deficiency, and RBC transfusion [43,44], and our study was not designed to investigate this issue. Fifth, A-V O 2diff measurement requires a correctly placed central venous catheter; although widely used in critically ill patients, the central venous catheter is not always available or not placed in the superior vena cava.…”

Interest of Treating Iron Deficiency, Diagnosed According to Hepcidin Quantification, on Outcomes After a Prolonged Icu Stay Compared to Standard Care: A Multicenter, Randomized, Single-blinded Trial

“…Indeed, giving intravenous iron to patients without ID may increase the risk of iron side-effects and of iron overload; whereas giving iron in critically ill patients with ID does not expose to an increased risk of oxidative stress [24]. Second, we used a new biomarker to identify ID, hepcidin [4,5,14,15], because standard laboratory tests are not usable in presence of in ammation [13,25,26]. We used a validated mass spectrometry method [17], which is relatively cheap and easy to obtain .…”

“…In the last decades, the understanding of iron metabolism has been markedly improved by the discovery of its master regulator, hepcidin [4]. A low hepcidin level has been shown to indicate ID in critically ill patients [4,5,14,15]. Data on hepcidin analysis in ICU suggests that 37% of patients have ID on ICU discharge and this group of patients had worse outcomes at one year, a low hepcidin being an independent predictor of one-year post-ICU mortality [15].…”

Parenteral Provision of Micronutrients to Adult Patients: An Expert Consensus Paper

“…A recent study based on hepcidin‐assisted deficiency diagnosis showed it to be present in over 30% of patients. It contributes significantly to fatigue observed after discharge . Recently, a better understanding of Fe metabolism has shown that blood hepcidin may assist in diagnosing Fe deficiency in the presence of inflammation and is currently under investigation .…”

“…It contributes significantly to fatigue observed after discharge. 95 Recently, a better understanding of Fe metabolism has shown that blood hepcidin may assist in diagnosing Fe deficiency in the presence of inflammation 96 and is currently under investigation. 97 The benefits of short-term IV supplementation (0.5-1 g for a few days) in reducing transfusion requirement have not yet been proven, 98 but the trials have shown no increase in infectious complications, 98,99 which were previously considered a prohibitive risk.…”