Iron deficiency and iron therapy in heart failure and chronic kidney disease

Preparation, characterization, and bioavailability evaluation of antioxidant phosvitin peptide-ferrous complex

BACKGROUND

Iron deficiency anemia (IDA) is one of the commonest global nutritional deficiency diseases, and the low bioavailability of iron is a key contributing factor. The peptide-iron complex could be used as a novel iron supplement to improve iron bioavailability.

RESULTS

In this study, antioxidant low molecular weight (<3 kDa) phosvitin peptide (named PP-4) was separated to prepare a phosvitin peptide-ferrous complex (named PP-4-Fe); then the structural conformation of PP-4-Fe was characterized and its bioavailability by in vitro digestion was evaluated. The results showed that PP-4 had good ferrous-binding activity with 96.14 ± 2.86 μg Fe2+ mg-1 , and had a strong antioxidant effect with 995.61 ± 79.75 μmol TE mg-1 in 2,2'-azinobis'3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) and 62.3 ± 3.95 μmol FeSO4 mg-1 in ferric ion reducing antioxidant power (FRAP). After ferrous binding, the FRAP activity of PP-4-Fe, enhanced by 1.8 times, formed a more ordered structure with an increase in α-helix and decrease in γ-random coil. The ferrous binding sites of PP-4 involved were the amino, carboxyl, imidazole, and phosphate groups. The PP-4-Fe complex displayed excellent gastrointestinal stability and antioxidant effects during digestion. The iron dialysis percentage of PP-4-Fe was 74.59% ± 0.68%, and increased to 81.10% ± 0.89% with the addition of 0.25 times vitamin C (VC). This indicated that PP-4-Fe displayed excellent bioavailability and VC in sufficient quantities had a synergistic effect on improving bioavailability.

CONCLUSIONS

This study demonstrated that antioxidant phosvitin peptide was an efficient delivery system to protect ferrous ions and suggested that the phosvitin peptide-ferrous complex has strong potential as a ferrous supplement. © 2023 Society of Chemical Industry.

Iron overload in hemodialysis patients: Comparison of serum iron parameters with T2* MRI sequence

PURPOSE

To evaluate correlation between serum iron parameters and liver T2* value in hemodialysis patients with iron overload due to parenteral iron therapy.

MATERIALS AND METHODS

We evaluated 30 hemodialysis patients using a multiecho T2*-weighted MRI sequence. Age, sex, duration of dialysis, iron and erythropoietin doses taken in the past year, and serum iron parameters were recorded. Liver T2* values were averaged from three distinct liver regions. A T2* value of 33 ± 7 ms is considered normal. Declines below 24, 21, and 14 ms signify iron overload grades 1, 2, and 3, respectively.

RESULTS

There was no statistically significant difference comparing the measurements of 3 different ROIs (p > 0.05). A total of 23 patients (76.6%) had iron overload. Serum ferritin levels of patients with iron overload were significantly higher than those without iron overload (687.25 [186.5-1489] ng/mL vs. 371.25 [127.5-542.5] ng/mL, p = 0.008). No linear correlation was observed between age, dialysis duration, serum iron metrics, medication doses, and T2* values. Likewise, no significant differences were found among patients based on iron overload status or its grades concerning these parameters.

CONCLUSION

While standard serum markers might overlook iron overload, elevated ferritin levels are promising. MRI reliably detects iron overload in patients receiving parenteral iron.

Association between Iron Status and Survival in Patients on Chronic Hemodialysis

The aim of this study was to evaluate survival rates according to iron status in patients undergoing maintenance hemodialysis (HD). Thus, the National HD Quality Assessment Program dataset and claims data were used for analysis (n = 42,390). The patients were divided into four groups according to their transferrin saturation rate and serum ferritin levels: Group 1 (n = 34,539, normal iron status); Group 2 (n = 4476, absolute iron deficiency); Group 3 (n = 1719, functional iron deficiency); Group 4 (n = 1656, high iron status). Using univariate and multivariable analyses, Group 1 outperformed the three other groups in terms of patient survival. Using univariate analysis, although Group 2 showed a favorable trend in patient survival rates compared with Groups 3 and 4, the statistical significance was weak. Group 3 exhibited similar patient survival rates to Group 4. Using multivariable Cox regression analysis, Group 2 had similar patient survival rates to Group 3. Subgroup analyses according to sex, diabetic status, hemoglobin level ≥ 10 g/dL, and serum albumin levels ≥ 3.5 g/dL indicated similar trends to those of the total cohort. However, subgroup analysis based on patients with a hemoglobin level < 10 g/dL or serum albumin levels < 3.5 g/dL showed a weak statistical significant difference compared with those with hemoglobin level ≥ 10 g/dL, or serum albumin levels ≥ 3.5 g/dL. In addition, the survival difference between Group 4 and other groups was greater in old patients than in young ones. Patients with a normal iron status had the highest survival rates. Patient survival rates were similar or differed only modestly among the groups with abnormal iron status. In addition, most subgroup analyses revealed similar trends to those according to the total cohort. However, subgroup analyses based on age, hemoglobin, or serum albumin levels showed different trends.

Correlation between galectin-3, RDW, Hepc, HS and ferritin and prognosis of patients with acute onset of chronic heart failure

Background

Chronic heart failure (CHF) is characterized by a high hospitalization rate and a high mortality rate. It is particularly important to identify biomarkers for predicting the prognosis of patients with acute attack of CHF.

Purpose

To observe the correlation between galectin-3, RDW, Hepc, HS and ferritin and the prognosis of patients with acute onset of CHF.

Methods

The study included 92 patients with acute onset of CHF who received treatment at our hospital between August 2020 and December 2021. After treatment, the patients were divided into the effective group and the non-effective group based on the effectiveness of treatment. The levels of galectin-3, RDW, Hepc, HS and ferritin before and after treatment were compared between the two groups and the correlation between prognosis of patients with acute attack of CHF and galectin-3, RDW, Hepc, HS and ferritin was observed.

Results

The effective rate was 71.74% (66/92) and the ineffective rate was 28.26% (26/92) in the 92 patients with acute attack of CHF in the study. Before and after treatment, the levels of galectin-3, RDW, Hepc, and HS were lower in the effective group than those of the non-effective group while the level of ferritin was higher in the effective group than that of the non-effective group (P < 0.05). Spearman correlation analysis showed that the level of prognosis of patients with acute attack of CHF was positively correlated with galectin-3, RDW, Hepc, and HS (r = 0.217, 0.109, 0.376, 0.765, P = 0.026, 0.032, 0.021, 0.006), and negatively correlated with ferritin (r = − 0.127, P = 0.037). The independent variables were galectin-3, RDW, Hepc, HS and ferritin and the dependent variable was prognosis of patients with acute attack of CHF. Univariate logistic regression analysis showed that alectin-3, RDW, Hepc, HS, and ferritin were protective factors for the prognosis of patients with acute attack of CHF. The independent variables were galectin-3, RDW, Hepc, HS and ferritin, dependent variables and the dependent variable was prognosis of patients with acute attack of CHF. Multivariate logistic regression analysis revealed that galectin-3, RDW, and Hepc were risk factors of the prognosis of patients with acute attack of CHF.

Conclusion

Galectin-3, RDW, Hepc, HS and ferritin were closely related with the prognosis of patients with acute attack of CHF and galectin-3, RDW, and Hepc were risk factors of the prognosis of patients with acute attack of CHF.