Acute and Subacute Effects of EV Iron Sucrose on Endothelial Functions in Hemodialysis Patients

Long-Term Intravenous Iron Therapy and Morbidity in Hemodialysis Patients

Objective: The aim of this study was to describe long-term intravenous iron therapy-associated morbidity in hemodialysis patients from a single Hemodialysis Center. Material and methods: We conducted an observational retrospective cohort study from 01 January to 31 December 2015. Two hundred and twenty prevalent patients on maintenance hemodialysis therapy for at least 12 months (mean age 53±13 years, 56% males, median hemodialysis vintage 5 (1-26) years) were included. Diabetic nephropathy as primary kidney disease, pregnancy and incomplete data records regarding study aims were exclusion criteria. We compared the frequency, duration and causes of hospitalizations in iron sucrose-treated versus gender and age-matched iron non-treated patients. Differences between groups were assessed using Chi-square and Kruskal-Wallis H tests. A p value μ0.05 was considered statistically significant. Results: From the entire cohort, 68% were iron-treated. One in five patients were treated with higher doses (400 mg monthly), and lower doses were used (100-200 mg monthly) in 80% of patients. There were no differences regarding the rates of admission between the two groups (56/100 patient-years in the iron sucrose-treated vs. 50/100 patient-years in the iron-untreated group, p=0.1). Still, the hospitalization rate significantly increased with the administered iron dose (0.4 vs. 0.7 vs. 0.8/100 patient-years for 100 mg vs. 200 mg vs. 400 mg monthly, respectively, p=0.006). Hospitalization rates due to infectious and cardiovascular diseases were similar for both groups (12/100 patient-years vs. 5.7/100 patient-years, p=0.3 and 11.3/100 patient-years vs. 4.3/100 patient-years, p=0.2, respectively). Conclusion: Higher doses of intravenous iron sucrose appear to be associated with an elevated risk of hospitalization. Nonetheless, long-term intravenous iron therapy seems to have a limited influence in terms of specific cause of morbidity in non-diabetic hemodialysis patients.

Acute Effects of Iron Sucrose and Iron Carboxymaltose on Endothelial Function in Nondialysis Chronic Kidney Disease Patients

BACKGROUND

Intravenous iron is commonly prescribed in chronic kidney disease (CKD) patients. Iron sucrose (IS) and ferric carboxymaltose (FCM) are 2 frequently used formulations. Experimental data showed that this 2 intravenous iron preparations have different potential to induce oxidative stress and by that endothelial dysfunction. Still, direct comparisons in clinical settings are rather scarce.

STUDY QUESTION

Are there any acute changes in endothelial function after single intravenous iron infusions of IS and FCM in nondialysis CKD patients?

STUDY DESIGN

This was a prospective, crossover study in which 31 patients with CKD stages 3-5 (80% stages 3 and 4, 81% female, 55% older than 60 years, 23% diabetes mellitus, and 94% arterial hypertension) who required intravenous iron as part of their routine medical care were enrolled.

MEASURES AND OUTCOMES

The effect of flow-mediated vasodilatation infusions containing 250-mL 10% glucose, 500-mg FCM, and 200-mg IS, both in 250-mL 0.9% saline solution, was compared. The infusions were administered over 30 minutes, 72 hours apart, in the mentioned order. Ultrasound measurement of the brachial artery flow-mediated vasodilation (FMD) performed 15 minutes before and after each infusion was used to assess endothelial function. The outcome was the post/preinfusion difference (Δ) in FMD.

RESULTS

The baseline FMD was similar before each study intervention. The arterial reactivity significantly decreased only after IS infusion [ΔFMD -2.3 (-5.65 to -0.33) vs. 1.0 (-1.49 to 1.80) after glucose, P = 0.01], but not after FCM [ΔFMD -0.8 (-2.50 to 0.65), P = 0.27 vs. glucose]. Moreover, the arterial reactivity was higher after IS as compared to FCM.

CONCLUSIONS

Endothelial dysfunction seems to be acutely induced by a single dose of intravenous IS, but not by FCM, in nondialysis CKD patients.

Oxidative stress, HDL functionality and effects of intravenous iron administration in women with iron deficiency anemia

BACKGROUND AND AIMS

Iron deficiency anemia (IDA) affects around 20-30% of adults worldwide. An association between IDA and cardiovascular disease (CVD) has been reported. Oxidative stress, inflammation and low concentration of high-density lipoproteins (HDL) were implicated on endothelial dysfunction and CVD in IDA. We studied the effects of iron deficiency and of an intravenous iron administration on oxidative stress and HDL characteristics in IDA women.

METHODS

Two studies in IDA women are presented: a case-control study, including 18 patients and 18 age-matched healthy women, and a follow-up study 72hr after the administration of intravenous iron (n = 16). Lipids, malondialdehyde, cholesteryl ester transfer protein (CETP), paraoxonase-1 (PON-1) and HDL chemical composition and functionality (cholesterol efflux and antioxidative activity) were measured. Cell cholesterol efflux from iron-deficient macrophages to a reference HDL was also evaluated.

RESULTS

IDA patients showed higher triglycerides and CETP activity and lower HDL-C than controls (all p < 0.001). HDL particles from IDA patients showed higher triglyceride content (+30%,p < 0.05) and lower antioxidative capacity (-23%,p < 0.05). Although HDL-mediated cholesterol efflux was similar between the patients and controls, iron deficiency provoked a significant reduction in macrophage cholesterol efflux (-25%,p < 0.05). Arylesterase activity of PON-1 was significantly lower in IDA patients than controls (-16%,p < 0.05). The intravenous administration of iron was associated with a decrease in malondialdehyde levels and an increase in arylesterase activity of PON-1 (-22% and +18%, respectively, p < 0.05).

CONCLUSION

IDA is associated with oxidative stress and functionally deficient HDL particles. It remains to be determined if such alterations suffice to impair endothelial function in IDA.

Involvement of iron-evoked oxidative stress in smoking-related endothelial dysfunction in healthy young men

Background

Oxidative stress and smoking contribute to endothelial dysfunction. Iron might also play a role in oxidative stress generation and endothelial dysfunction. However, the involvement of iron in smoking-induced endothelial dysfunction in healthy smokers remains unclear. Therefore, we examined here whether (1) intravenous iron infusion impaired endothelial function evaluated by flow-mediated vasodilatation (FMD) in non-smokers, and (2) deferoxamine, a potent iron chelator, ameliorated endothelial dysfunction in healthy smokers.

Methods

Eight healthy young male non-smokers (23±4 years old) received intravenous injection of saccharated ferric oxide (0.7 mg/kg body weight), while 10 age-matched healthy male smokers received deferoxamine mesylate (8.3 mg/kg body weight). At baseline, 5 and 20 minutes after treatment with iron or deferoxamine, biochemical variables were measured, including serum iron and marondialdehyde (MDA), a marker of lipid oxidation, and endothelial function was simultaneously evaluated by FMD.

Results

Compared with non-smokers, FMD was significantly lower in smokers. Iron and MDA levels were significantly increased, whereas FMD was impaired by iron infusion in non-smokers. Conversely, deferoxamine treatment significantly decreased iron and MDA levels and restored the decreased FMD in smokers. Baseline serum iron and MDA levels in all 18 subjects (non-smokers and smokers) were correlated with each other. There was a significant inverse correlation between the changes in MDA values and FMD from baseline in 18 men. Endothelium-independent vasodilation by glyceryl trinitrate was unaltered by either treatment.

Conclusions

Our present study suggests that iron-evoked oxidative stress might play a role in endothelial dysfunction in healthy smokers.