Low preoperative hepcidin concentration as a risk factor for mortality after cardiac surgery: A pilot study

Elevated plasma hepcidin concentrations are associated with an increased risk of mortality and nonfatal cardiovascular events in patients with type 2 diabetes: a prospective study

BACKGROUND

The effect of plasma hepcidin concentrations on the long-term risk of developing adverse cardiovascular outcomes in people with type 2 diabetes mellitus (T2DM) is unclear.

METHODS

We followed for a median of 55.6 months 213 outpatients with established T2DM (45.5% women, mean age 69 ± 10 years; BMI 28.7 ± 4.7 kg/m2; median diabetes duration 11 years). Baseline plasma ferritin and hepcidin concentrations were measured with an electrochemiluminescence immunoassay and mass spectrometry-based assay, respectively. The primary study outcome was a composite of all-cause mortality or incident nonfatal cardiovascular events (inclusive of myocardial infarction, permanent atrial fibrillation, ischemic stroke, or new hospitalization for heart failure).

RESULTS

42 patients developed the primary composite outcome over a median follow-up of 55.6 months. After stratifying patients by baseline hepcidin tertiles [1st tertile: median hepcidin 1.04 (IQR 0.50-1.95) nmol/L, 2nd tertile: 3.81 (IQR 3.01-4-42) nmol/L and 3rd tertile: 7.72 (IQR 6.37-10.4) nmol/L], the risk of developing the primary composite outcome in patients in the 3rd tertile was double that of patients in the 1st and 2nd tertile combined (unadjusted hazard ratio [HR] 2.32, 95%CI 1.27-4.26; p = 0.007). This risk was not attenuated after adjustment for age, sex, adiposity measures, smoking, hypertension, statin use, antiplatelet medication use, plasma hs-C-reactive protein and ferritin concentrations (adjusted HR 2.53, 95%CI 1.27-5.03; p = 0.008).

CONCLUSIONS

In outpatients with T2DM, higher baseline hepcidin concentrations were strongly associated with an increased long-term risk of overall mortality or nonfatal cardiovascular events, even after adjustment for established cardiovascular risk factors, plasma ferritin concentrations, medication use, and other potential confounders.

NT-proBNP/urine hepcidin-25 ratio and cardiorenal syndrome type 1 in patients with severe symptomatic aortic stenosis

Background: This study aimed to determine whether novel and conventional cardiorenal biomarkers in patients before transcatheter aortic valve implantation may be associated with cardiorenal syndrome (CRS) type 1. Methods: Serum NT-proBNP and urine biomarkers (hepcidin-25, NGAL, IL-6) were measured before and 24 h after transcatheter aortic valve implantation. Results: 16/95 patients had CRS type 1. Those patients had longer length of stay in hospital (12.5 [9.0-16.0] vs 9.0 [8-12] days; p = 0.025) and were more frequently readmitted to hospital within 6 months after discharge (46.7 vs 15.6%; odds ratio: 4.7; 95% CI: 1.5-15.5; p = 0.007). The NT-proBNP/urine hepcidin-25 ratio (odds ratio: 2.89; 95% CI: 1.30-6.41; p = 0.009) was an independent modifier of CRS type 1. Conclusion: The NT-proBNP/urine hepcidin-25 ratio appears to be a modifier of risk of CRS type 1.

In-depth review: is hepcidin a marker for the heart and the kidney?

Iron is an essential trace element involved in oxidation-reduction reactions, oxygen transport and storage, and energy metabolism. Iron in excess can be toxic for cells, since iron produces reactive oxygen species and is important for survival of pathogenic microbes. There is a fine-tuning in the regulation of serum iron levels, determined by intestinal absorption, macrophage iron recycling, and mobilization of hepatocyte stores versus iron utilization, primarily by erythroid cells in the bone marrow. Hepcidin is the major regulatory hormone of systemic iron homeostasis and is upregulated during inflammation. Hepcidin metabolism is altered in chronic kidney disease. Ferroportin is an iron export protein and mediates iron release into the circulation from duodenal enterocytes, splenic reticuloendothelial macrophages, and hepatocytes. Systemic iron homeostasis is controlled by the hepcidin-ferroportin axis at the sites of iron entry into the circulation. Hepcidin binds to ferroportin, induces its internalization and intracellular degradation, and thus inhibits iron absorption from enterocytes, and iron release from macrophages and hepatocytes. Recent data suggest that hepcidin, by slowing or preventing the mobilization of iron from macrophages, may promote atherosclerosis and may be associated with increased cardiovascular disease risk. This article reviews the current data regarding the molecular and cellular pathways of systemic and autocrine hepcidin production and seeks the answer to the question whether changes in hepcidin translate into clinical outcomes of all-cause and cardiovascular mortality, and cardiovascular and renal end-points.

Hepcidin - Potential biomarker of contrast-induced acute kidney injury in patients undergoing percutaneous coronary interventions

PURPOSE

Contrast-induced acute kidney injury (CI-AKI) is a common and potentially serious complication of percutaneous coronary interventions (PCI). In this study, we tested the hypothesis whether serum and urinary hepcidin could represent early biomarkers of CI-AKI in patients with normal serum creatinine undergoing PCI. In addition, we assessed serum and urinary neutrophil gelatinase-associated lipocalin (NGAL), cystatin C, eGFR and serum creatinine in these patients.

METHODS

Serum and urinary hepcidin and NGAL, serum cystatin C, were evaluated before, and after 2, 4, 8, 24 and 48 h after PCI using commercially available kits. Serum creatinine was assessed before, 24 and 48 h after PCI.

RESULTS

We found a significant rise in serum hepcidin as early as after 4 and 8 h when compared to the baseline values. Serum NGAL increased after 2, 4 and 8 h, and in urinary NGAL after 4, 8 and 24 h after PCI. We found a significant fall in urinary hepcidin after 8 and 24 h after PCI. Serum cystatin C increased significantly 8 h after PCI, reaching peak 24 h after PCI and then decreased after 48 h. The prevalence of CI-AKI was 8%. Urine hepcidin was significantly lower 8 and 24 h after PCI in patients with CI-AKI, while serum and urine NGAL were significantly higher in patients with CI-AKI.

CONCLUSIONS

Our findings suggest that serum hepcidin might be an early predictive biomarker of ruling out CI-AKI after PCI, thereby contributing to early patient risk stratification. However, our data needs to be validated in large cohorts with various stages of CKD.

Interleukin-6 and hepcidin expression changes in cardiac tissue of long-term trained and untrained rats after exhaustive exercise

Background/aim: Exercise benefits the cardiovascular system, but strenuous exercise can cause cardiac damage and induce cytokine production, particularly that of interleukin-6 (IL-6). Hepcidin, which is primarily regulated by IL-6, increases after exercise. Hepcidin is a possible protective factor against the adverse effects of strenuous exercise such as oxidative stress. The aim of the study is to reveal that training increases hepcidin and attenuates increased levels of IL-6 in the hearts of exhaustively exercised rats by comparing the IL-6 and hepcidin mRNA expression levels in trained and untrained groups.Materials and methods: Thirty male Wistar albino rats were assigned to the following groups: sedentary controls (Con); untrained animals that acutely completed exhaustive exercise and were sacrificed immediately after exhaustion (UT-i) or 1 day after exhaustion (UT-1); and long-term trained animals that completed exhaustive exercise and were sacrificed immediately after exhaustion (T-i) or 1 day after exhaustion (T-1). mRNA levels were examined by reverse transcription PCR. Results: IL-6 levels significantly increased in the UT-i, T-i, and T-1 groups compared to the Con group (P = 0.000, P = 0.024, P = 0.001), with maximal IL-6 expression found in the UT-i group. Hepcidin levels significantly increased in the T-1 group (P = 0.000) compared to the control. Conclusion: Increased IL-6 levels in rats show that exhaustive exercise can cause cardiac inflammation. However, long-term training attenuated the severity of the inflammation. The possible protective effect of increased hepcidin in the trained groups can be explained by the antiinflammatory effects of IL-6 and long-term training.