High incidence of iron depletion and restless leg syndrome (RLS) in regular blood donors: intravenous iron sucrose substitution more effective than oral iron

Restless legs syndrome: From clinic to personalized medicine

Restless legs syndrome (RLS) is a common neurological sensorimotor disorder that impairs sleep, mood and quality of life. RLS is defined by an urge to move the legs at rest that increases in the evening and at night, and is frequently associated with metabolic and cardiovascular diseases. Symptoms frequency, age at RLS onset, severity, familial history and consequences of RLS vary widely between patients. A genetic susceptibility, iron deficiency, dopamine deregulation, and possible hypo-adenosinergic state may play a role in the pathophysiology of RLS. Polysomnographic recordings found often periodic leg movements during sleep and wakefulness in patients with RLS. RLS can be classified as primary or comorbid with major diseases: iron deficiency, renal, neurological, rheumatological and lung diseases. First-line treatments are low-dose dopamine agonists, and alpha-2-delta ligands depending on the clinical context, and second/third line opiates for pharmacoresistant forms of RLS. Augmentation syndrome is a serious complication of dopamine agonists and should be prevented by using the recommended low dose. Despite an increase in knowledge, RLS is still underdiagnosed, poorly recognized, resulting in substantial individual health burden and socioeconomic coast, and education is urgently needed to increase awareness of this disabling disorder.

Iron Supplementation and Exercise During Pregnancy: Effects on Behavior and the Dopaminergic System

Although it is known that regular physical activity is recommended as part of a healthy lifestyle, the number of data concerning efficacy of exercise and your relationship with a demand for iron during pregnancy is limited. The purpose of this study was to evaluate the relationship between iron supplementation and exercise during pregnancy on the behavior of rats. Molecular variables dopamine transporter (DAT) and dopamine receptor (D2) related to the locomotor behavior in response to the exercise and the iron supplemented diet were investigated. Sixty-day-old female Wistar rats were used. The pregnant rats were distributed into the following groups: standard diet (SD, n = 7), iron supplementation (IS, n = 9), exercise (EX, n = 10), and exercise + iron supplementation (EX + IS, n = 9). All rats in both the pregnant and non-pregnant groups were submitted to open-field tests. The iron supplementation diet was shown to reduce locomotor behaviors, with reduced central and peripheral ambulation, reduced rearing, and increased freezing. On the other hand, physical exercise caused an increase in central and peripheral ambulation, and in rearing. The expression of the D2 receptor protein and the dopamine transporter DAT did not show changes with the interventions over 21 days of pregnancy. In this context, the present study demonstrated that both iron supplementation and exercise exerted an influence during pregnancy on the behavior of rats, however, with different effects.

Iron Deficiency and Blood Donation: Links, Risks and Management

The purpose of this review is to raise awareness about the frequently underappreciated association of blood donation with iron deficiency, and to describe methods for its prevention and management. Blood donors cannot expect any health benefits from the donation but have justified expectations of no harm. Iron deficiency without anemia (IDWA) and iron deficiency anemia (IDA) are common consequences of regular blood donation, and this activity is the most important factor affecting iron status in regular blood donors. Awareness of blood donation as a primary cause of sideropenia is surprisingly low among physicians. Blood donation screening identifies potential donors with IDA but is frequently inadequate to detect IDWA. For the assessment of body iron stores, plasma or serum ferritin, transferrin saturation (TSAT) and soluble transferrin receptors (sTfR) concentrations are the most widely used biochemical markers, although the percentage of hypochromic mature erythrocytes and the hemoglobin content of reticulocytes are also useful. IDWA can be prevented by limiting the total volume of blood collected, by iron deficiency screening and deferral of sideropenic donors, by prolonging the interdonation intervals, and by iron supplementation between donations. IDWA tends to be more prevalent in younger people, females, and high-intensity donors. A potentially effective strategy to address sideropenia in blood donors is serum ferritin testing, but this may lead to a higher rate of deferral. Most regular blood donors cannot replenish their iron deficit by an iron-rich diet alone and will benefit from low-dose oral iron administration with various commercially available products post-donation, a well-tolerated strategy. However, valid concerns exist regarding the possibility of worsening the iron overload in donors with undiagnosed hemochromatosis or masking the symptoms of a clinically important gastrointestinal hemorrhage or other underlying medical condition. Finally, educational efforts should be intensified to improve the awareness of blood donation as a primary cause of iron deficiency among physicians of all specialties.

Ferritin Trajectories over Repeated Whole Blood Donations: Results from the FIND+ Study

BACKGROUND

Depending on post-donation erythropoiesis, available iron stores, and iron absorption rates, optimal donation intervals may differ between donors. This project aims to define subpopulations of donors with different ferritin trajectories over repeated donations.

METHODS

Ferritin levels of 300 new whole blood donors were measured from stored (lookback) samples from each donation over two years in an observational cohort study. Latent classes of ferritin level trajectories were investigated separately using growth mixture models for male and female donors. General linear mixed models assessed associations of ferritin levels with subsequent iron deficiency and/or low hemoglobin.

RESULTS

Two groups of donors were identified using group-based trajectory modeling in both genders. Ferritin levels showed rather linear reductions among 42.9% of male donors and 87.7% of female donors. For the remaining groups of donors, steeper declines in ferritin levels were observed. Ferritin levels at baseline and the end of follow-up varied greatly between groups.

CONCLUSIONS

Repeated ferritin measurements show depleting iron stores in all-new whole blood donors, the level at which mainly depends on baseline ferritin levels. Tailored, less intensive donation strategies might help to prevent low iron in donors, and could be supported with ferritin monitoring and/or iron supplementation.

Risk of Infection Associated With Administration of Intravenous Iron: A Systematic Review and Meta-analysis

IMPORTANCE

Intravenous iron is recommended by many clinical guidelines based largely on its effectiveness in reducing anemia. However, the association with important safety outcomes, such as infection, remains uncertain.

OBJECTIVE

To examine the risk of infection associated with intravenous iron compared with oral iron or no iron.

DATA SOURCES

Medline, Embase, and Cochrane Central Register of Controlled Trials (CENTRAL) were searched for randomized clinical trials (RCTs) from 1966 to January 31, 2021. Ongoing trials were sought from ClinicalTrials.gov, CENTRAL, and the World Health Organization International Clinical Trials Search Registry Platform.

STUDY SELECTION

Pairs of reviewers identified RCTs that compared intravenous iron with oral iron or no iron across all patient populations, excluding healthy volunteers. Nonrandomized studies published since January 1, 2007, were also included. A total of 312 full-text articles were assessed for eligibility.

DATA EXTRACTION AND SYNTHESIS

Data extraction and risk of bias assessments were performed according to the Preferred Reporting Items of Systematic Reviews and Meta-analyses (PRISMA) and Cochrane recommendations, and the quality of evidence was assessed using the GRADE (Grades of Recommendation, Assessment, Development, and Evaluation) approach. Two reviewers extracted data independently. A random-effects model was used to synthesize data from RCTs. A narrative synthesis was performed to characterize the reporting of infection.

MAIN OUTCOMES AND MEASURES

The primary outcome was risk of infection. Secondary outcomes included mortality, hospital length of stay, and changes in hemoglobin and red blood cell transfusion requirements. Measures of association were reported as risk ratios (RRs) or mean differences.

RESULTS

A total of 154 RCTs (32 920 participants) were included in the main analysis. Intravenous iron was associated with an increased risk of infection when compared with oral iron or no iron (RR, 1.17; 95% CI, 1.04-1.31; I2 = 37%; moderate certainty of evidence). Intravenous iron also was associated with an increase in hemoglobin (mean difference, 0.57 g/dL; 95% CI, 0.50-0.64 g/dL; I2 = 94%) and a reduction in the risk of requiring a red blood cell transfusion (RR, 0.93; 95% CI, 0.76-0.89; I2 = 15%) when compared with oral iron or no iron. There was no evidence of an effect on mortality or hospital length of stay.

CONCLUSIONS AND RELEVANCE

In this large systematic review and meta-analysis, intravenous iron was associated with an increased risk of infection. Well-designed studies, using standardized definitions of infection, are required to understand the balance between this risk and the potential benefits.

The effects of intravenous iron supplementation on fatigue and general health in non-anemic blood donors with iron deficiency: a randomized placebo-controlled superiority trial

We investigated whether intravenous iron supplementation improves fatigue and general health in non-anemic repeat adult blood donors with iron deficiency (ferritin ≤ 50 µg/L). Of 1,487 potentially eligible participants, 203 were randomly assigned to a single intravenous dose of 800 mg iron-carboxymaltose and 202 to placebo; 393 participants completed the trial. At 6 to 8 weeks after intervention, self-rated mean fatigue scores (numeric rating scale from 1-10, primary outcome) were 3.9 ± 1.8 in the iron supplementation group and 4.0 ± 2.2 in the placebo group, showing no group difference (p = 0.819). Pre-specified subgroup analyses of gender, ferritin < 25 µg/L and fatigue ≥ 4 points, as well as exploratory analyses of lower ferritin cut-offs did not reveal any between-group differences. In terms of secondary outcomes, the mean differences were 114.2 µg/L for ferritin (95% CI 103.1-125.3) and 5.7 g/L for hemoglobin (95% CI 4.3-7.2) with significantly higher values in the iron supplementation group. No group differences were observed for different measures of general well-being and other clinical and safety outcomes. Intravenous iron supplementation compared with placebo resulted in increase of ferritin and hemoglobin levels in repeat blood donors with low iron stores, yet had no effect on fatigue and general well-being.

The Effect of Parenteral or Oral Iron Supplementation on Fatigue, Sleep, Quality of Life and Restless Legs Syndrome in Iron-Deficient Blood Donors: A Secondary Analysis of the IronWoMan RCT

Background: Besides anemia, iron deficiency may cause more subtle symptoms, including the restless legs syndrome (RLS), the chronic fatigue syndrome (CFS) or sleeping disorders. Objective: The aim of this pre-planned secondary analysis of the IronWoMan randomized controlled trial (RCT) was to compare the frequency and severity of symptoms associated with iron deficiency before and after (intravenous or oral) iron supplementation in iron deficient blood donors. Methods/Design: Prospective, randomized, controlled, single-centre trial. (ClinicalTrials.gov: NCT01787526). Setting: Tertiary care center in Graz, Austria. Participants: 176 (138 female and 38 male) whole-blood and platelet apheresis donors aged ≥ 18 and ≤ 65 years with iron deficiency (ferritin ≤ 30ng/mL at the time of blood donation). Interventions: Intravenous iron (1 g ferric carboxymaltose, n = 86) or oral iron supplementation (10 g iron fumarate, 100 capsules, n = 90). Measurements: Clinical symptoms were evaluated by a survey before iron therapy (visit 0, V0) and after 8–12 weeks (visit 1, V1), including questions about symptoms of restless legs syndrome (RLS), chronic fatigue syndrome (CFS), sleeping disorders, quality of life and symptoms like headaches, dyspnoea, dizziness, palpitations, pica and trophic changes in fingernails or hair. Results: We found a significant improvement in the severity of symptoms for RLS, fatigue and sleep quality (p < 0.001). Furthermore, a significant decrease in headaches, dyspnoea, dizziness and palpitations was reported (p < 0.05). There was no difference between the type of iron supplementation (intravenous versus oral) and clinical outcome data. Conclusion: Iron supplementation in iron-deficient blood donors may be an effective strategy to improve symptoms related to iron deficiency and the wellbeing of blood donors.

Iron Sucrose: A Wealth of Experience in Treating Iron Deficiency

Iron deficiency and iron-deficiency anemia are associated with increased morbidity and mortality in a wide range of conditions. In many patient populations, this can be treated effectively with oral iron supplementation; but in patients who are unable to take or who do not respond to oral iron therapy, intravenous iron administration is recommended. Furthermore, in certain conditions, such as end-stage kidney disease, chronic heart failure, and inflammatory bowel disease, intravenous iron administration has become first-line treatment. One of the first available intravenous iron preparations is iron sucrose (Venofer®), a nanomedicine that has been used clinically since 1949. Treatment with iron sucrose is particularly beneficial owing to its ability to rapidly increase hemoglobin, ferritin, and transferrin saturation levels, with an acceptable safety profile. Recently, important new data relating to the use of iron sucrose, including the findings from the landmark PIVOTAL trial in patients with end-stage kidney disease, have been reported. Several years ago, a number of iron sucrose similars became available, although there have been concerns about the clinical appropriateness of substituting the original iron sucrose with an iron sucrose similar because of differences in efficacy and safety. This is a result of the complex and unique physicochemical properties of nanomedicines such as iron sucrose, which make copying the molecule difficult and problematic. In this review, we summarize the evidence accumulated during 70 years of clinical experience with iron sucrose in terms of efficacy, safety, and cost-effectiveness.

Donor Iron Deficiency Study (DIDS): protocol of a study to test whether iron deficiency in blood donors affects red blood cell recovery after transfusion

BACKGROUND

Despite fulfilling all requirements for blood donation, a large proportion of regular blood donors are iron deficient. Red blood cells (RBC) from iron-deficient donors may be particularly susceptible to damage induced by standard refrigerated storage. Herein, we present a study protocol for testing whether correcting iron deficiency in donors with iron-deficient erythropoiesis will improve the quality of their refrigerator-stored RBC.

MATERIALS AND METHODS

This is a randomised, controlled, double-blind clinical trial. Sixty healthy regular donors who meet donation standards, while exhibiting iron-deficient erythropoiesis by laboratory testing criteria, will donate a single standard RBC unit that will be leucoreduced and stored in a refrigerator under standard conditions for 40-42 days. A 51Cr-radiolabelled 24-hour RBC recovery study will be performed and then these donors will be randomised to receive, in a double-blinded fashion, either intravenous saline, as a control, or low-molecular weight iron dextran (1 g), to provide total iron repletion. Four to six months later, they will donate a second RBC unit, which will be similarly stored, and autologous 51Cr-labelled 24-hour post-transfusion RBC recovery will again be determined.

RESULTS

The primary endpoint will be the change in 24-hour post-transfusion recovery from the first to the second donation. The primary outcome will be the group mean difference in the primary endpoints between the group receiving intravenous saline and the group receiving intravenous iron dextran. Secondary outcomes will be quality of life, fatigue, and emotional health, assessed by surveys.

CONCLUSION

This study will provide definitive evidence as to whether donor iron deficiency affects the quality of the blood supply and will assess the severity of symptoms affecting iron-deficient blood donors.

Iron supplementation for restless legs syndrome - A systematic review and meta-analysis

BACKGROUND

Iron supplementation, is recommended for the treatment of restless legs syndrome (RLS). We gathered evidence for the efficacy and safety of iron supplementation for RLS.

METHODS

A systematic review and meta-analysis of randomized controlled trials that compared iron supplementation versus no iron for patients with RLS was performed. Multiple databases were searched. The primary outcome was the effect of iron on the International Restless Legs Syndrome score (IRLSS) at 4 weeks after treatment. For dichotomous data, risk ratios (RR) with 95% confidence intervals (CIs) were estimated and pooled. For continuous data, weighted mean differences (WMD) were calculated.

RESULTS

Ten trials fulfilled the inclusion criteria. Iron therapy was associated with a significant decrease of the IRLSS of -3.55 [95% CI (-5.41) - (-1.68)] points and an increase in the percentage of patients with improvement of the IRLSS score, RR of 2.16 [95% CI 1.56-2.98]. IV FCM was associated with improvement in both the IRLSS (WMD of -2.79 (95% CI (-4.62) - (-0.96), 4 trials, I² = 0%) and on the RLS-QOL by WMD of 8.67 (95% CI 1.68-15). Iron was associated with an increased rate of adverse events RR 2.04 (95% CI 1.46-2.85), which were not severe and not associated with increased rate of treatment discontinuation.

CONCLUSION

Iron supplementation is associated with improvement of the IRLSS score. Our meta-analysis supports the use of iron, oral or IV, as effective therapy for patients with RLS. Further studies should assess subgroups of patients most likely to benefit from iron supplementation.

Iron for the treatment of restless legs syndrome

BACKGROUND

Restless legs syndrome (RLS) is a common neurologic disorder that is associated with peripheral iron deficiency in a subgroup of patients. It is unclear whether iron therapy is effective treatment for RLS.

OBJECTIVES

To evaluate the efficacy and safety of oral or parenteral iron for the treatment of restless legs syndrome (RLS) when compared with placebo or other therapies.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, Embase, PsycNFO, and CINAHL for the time period January 1995 to September 2017. We searched reference lists for additional published studies. We searched Clinicaltrials.gov and other clinical trial registries (September 2017) for ongoing or unpublished studies.

SELECTION CRITERIA

Controlled trials comparing any formulation of iron with placebo, other medications, or no treatment, in adults diagnosed with RLS according to expert clinical interview or explicit diagnostic criteria.

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted data and assessed trial quality, with discussion to reach consensus in the case of any disagreement. The primary outcome considered in this review was restlessness or unpleasant sensations, as experienced subjectively by the patient. We combined treatment/control differences in the outcomes across studies using random-effects meta-analyses. We analysed continuous data using mean differences (MDs) where possible and performed standardised mean difference (SMD) analyses when different measurements were used across studies. We calculated risk ratios (RRs) for dichotomous data using the Mantel-Haenszel method and 95% confidence intervals (CIs). We analysed study heterogeneity using the I² statistic. We used standard methodological procedures expected by Cochrane. We performed GRADE analysis using GRADEpro.

MAIN RESULTS

We identified and included 10 studies (428 total participants, followed for 2-16 weeks) in this review. Our primary outcome was restlessness or uncomfortable leg sensations, which was quantified using the International Restless Legs Scale (IRLS) (range, 0 to 40) in eight trials and a different RLS symptom scale in a ninth trial. Nine studies compared iron to placebo and one study compared iron to a dopamine agonist (pramipexole). The possibility for bias among the trials was variable. Three studies had a single element with high risk of bias, which was lack of blinding in two and incomplete outcome data in one. All studies had at least one feature resulting in unclear risk of bias.Combining data from the seven trials using the IRLS to compare iron and placebo, use of iron resulted in greater improvement in IRLS scores (MD -3.78, 95% CI -6.25 to -1.31; I²= 66%, 7 studies, 345 participants) measured 2 to 12 weeks after treatment. Including an eighth study, which measured restlessness using a different scale, use of iron remained beneficial compared to placebo (SMD -0.74, 95% CI -1.26 to -0.23; I² = 80%, 8 studies, 370 participants). The GRADE assessment of certainty for this outcome was moderate.The single study comparing iron to a dopamine agonist (pramipexole) found a similar reduction in RLS severity in the two groups (MD -0.40, 95% CI -5.93 to 5.13, 30 participants).Assessment of secondary outcomes was limited by small numbers of trials assessing each outcome. Iron did not improve quality of life as a dichotomous measure (RR 2.01, 95% CI 0.54 to 7.45; I²=54%, 2 studies, 39 participants), but did improve quality of life measured on continuous scales (SMD 0.51, 95% CI 0.15 to 0.87; I²= 0%, 3 studies, 128 participants), compared to placebo. Subjective sleep quality was no different between iron and placebo groups (SMD 0.19, 95% CI -0.18 to 0.56; I² = 9%, 3 studies, 128 participants), nor was objective sleep quality, as measured by change in sleep efficiency in a single study (-35.5 +/- 92.0 versus -41.4 +/- 98.2, 18 participants). Periodic limb movements of sleep were not significantly reduced with iron compared to placebo ( SMD -0.19, 95% CI -0.70 to 0.32; I² = 0%, 2 studies, 60 participants). Iron did not improve sleepiness compared to placebo, as measured on the Epworth Sleepiness Scale (data not provided, 1 study, 60 participants) but did improve the daytime tiredness item of the RLS-6 compared to placebo (least squares mean difference -1.5, 95% CI -2.5 to -0.6; 1 study, 110 participants). The GRADE rating for secondary outcomes ranged from low to very low.Prespecified subgroup analyses showed more improvement with iron in those trials studying participants on dialysis. The use of low serum ferritin levels as an inclusion criteria and the use or oral versus intravenous iron did not show significant subgroup differences.Iron did not result in significantly more adverse events than placebo (RR 1.48, 95% CI 0.97 to 2.25; I²=45%, 6 studies, 298 participants). A single study reported that people treated with iron therapy experienced fewer adverse events than the active comparator pramipexole.

AUTHORS' CONCLUSIONS

Iron therapy probably improves restlessness and RLS severity in comparison to placebo. Iron therapy may not increase the risk of side effects in comparison to placebo. We are uncertain whether iron therapy improves quality of life in comparison to placebo. Iron therapy may make little or no difference to pramipexole in restlessness and RLS severity, as well as in the risk of adverse events. The effect on secondary outcomes such as quality of life, daytime functioning, and sleep quality, the optimal timing and formulation of administration, and patient characteristics predicting response require additional study.

Management Strategies for Restless Legs Syndrome/Willis-Ekbom Disease During Pregnancy

Restless legs syndrome/Willis-Ekbom disease is a common disorder during pregnancy that may significantly impact on the health of affected women, leading to negative consequences in the short and long term. An accurate diagnosis helps to recognize the syndrome and choose the optimal therapeutic strategy, based on the characteristics and needs of the patient. This article summarizes the main treatment options recommended by the consensus clinical guidelines of the International Restless Legs Syndrome Study Group and provides a short guide to the management of restless leg syndrome during pregnancy in clinical practice.

Evidence-based and consensus clinical practice guidelines for the iron treatment of restless legs syndrome/Willis-Ekbom disease in adults and children: an IRLSSG task force report

BACKGROUND

Brain iron deficiency has been implicated in the pathophysiology of RLS, and current RLS treatment guidelines recommend iron treatment when peripheral iron levels are low. In order to assess the evidence on the oral and intravenous (IV) iron treatment of RLS and periodic limb movement disorder (PLMD) in adults and children, the International Restless Legs Syndrome Study Group (IRLSSG) formed a task force to review these studies and provide evidence-based and consensus guidelines for the iron treatment of RLS in adults, and RLS and PLMD in children.

METHODS

A literature search was performed to identify papers appearing in MEDLINE from its inception to July 2016. The following inclusion criteria were used: human research on the treatment of RLS or periodic limb movements (PLM) with iron, sample size of at least five, and published in English. Two task force members independently evaluated each paper and classified the quality of evidence provided.

RESULTS

A total of 299 papers were identified, of these 31 papers met the inclusion criteria. Four studies in adults were given a Class I rating (one for IV iron sucrose, and three for IV ferric carboxymaltose); only Class IV studies have evaluated iron treatment in children. Ferric carboxymaltose (1000 mg) is effective for treating moderate to severe RLS in those with serum ferritin <300 μg/l and could be used as first-line treatment for RLS in adults. Oral iron (65 mg elemental iron) is possibly effective for treating RLS in those with serum ferritin ≤75 μg/l. There is insufficient evidence to make conclusions on the efficacy of oral iron or IV iron in children.

CONCLUSIONS

Consensus recommendations based on clinical practice are presented, including when to use oral iron or IV iron, and recommendations on repeated iron treatments. New iron treatment algorithms, based on evidence and consensus opinion have been developed.

Iron-deficient erythropoiesis in blood donors and red blood cell recovery after transfusion: initial studies with a mouse model

BACKGROUND

Most frequent red cell (RBC) donors and many first-time donors are iron deficient, but meet haemoglobin standards. However, the effects of donation-induced iron deficiency on RBC storage quality are unknown. Thus, we used a mouse model to determine if donor iron deficiency reduced post-transfusion RBC recovery.

METHODS

Weanling mice received a control diet or an iron-deficient diet. A third group receiving the iron-deficient diet was also phlebotomised weekly. This provided 3 groups of mice with different iron status: (1) iron replete, (2) mild iron deficiency with iron-deficient erythropoiesis, and (3) iron-deficiency anaemia. At ten weeks of age, blood was collected, leucoreduced, and stored at 4 ºC. After 12 days of storage, 24-hour (h) post-transfusion RBC recovery was quantified in recipients by flow cytometry.

RESULTS

Before blood collection, mean haemoglobin concentrations in the iron-replete, iron-deficient, and iron-deficiency anaemia donor mice were 16.5±0.4, 11.5±0.4, and 7.0±1.4 [g/dL± 1 standard deviation (SD)], respectively (p<0.01 for all comparisons between groups). The 24-h post-transfusion RBC recoveries in recipients receiving transfusions from these three cohorts were 77.1±13.2, 66.5±10.9, and 46.7±15.9 (% ±1 SD), respectively (p<0.05 for all comparisons between groups).

DISCUSSION

In summary, donor iron deficiency significantly reduced 24-h post-transfusion RBC recovery in recipient mice. RBCs from mice with mild iron deficiency and iron-deficient erythropoiesis, with haemoglobin levels similar to those used for human autologous blood donation, had intermediate post-transfusion RBC recovery, as compared to iron-replete donors and those with iron-deficiency anaemia. This suggests that, in addition to the effects of iron deficiency on donor health, frequent blood donation, leading to iron-deficient erythropoiesis, may also have adverse effects for transfusion recipients.

High-dose intravenously administered iron versus orally administered iron in blood donors with iron deficiency: study protocol for a randomised, controlled trial

Background

About 2–3 % of the population participates in blood donation programmes. Each whole blood donation or ten apheresis donations cause a loss of 200–250 mg of iron. As a result, one of the most common risks of regular blood donors is iron deficiency. Although this has been known for decades, in most countries, iron status is currently not assessed or treated in this population. Premenopausal women are particularly affected, as they have lower iron reserves and higher daily requirements. Besides anaemia, iron deficiency may lead to fatigue and impaired cognitive and physical performance. Current iron preparations for intravenous administration are well tolerated and allow for application of large doses up to 1 g in one visit. Our hypothesis is that in blood donors with iron deficiency, intravenously administered iron is more efficient and as safe as oral iron supplementation. Since anaemia is one of the most frequent reasons for permanent or intermittent donor deferral, maintaining an iron-replete donor pool may help to prevent shortages in blood supply and to avoid iron deficiency-related comorbidities.

Methods/design

In this randomised clinical trial we include male and female blood donors aged ≥18 and ≤65 years with a ferritin value of ≤30 ng/ml. Stratified by gender, participants are randomized with a web-based randomisation tool in a 1:1 ratio to either 1 g of intravenously administered ferric carboxymaltose or 10 g of iron fumarate supplements at one to two daily doses of 100 mg each. Eight to 12 weeks after the first visit, iron status, blood count and symptoms are assessed in both groups. The primary endpoint is the difference in transferrin saturation (%) following the intervention between both groups. Secondary endpoints include other parameters of iron metabolism and red blood cell count, the number of patients with drug-related adverse events, and subjective symptoms including those of the restless legs syndrome, quality of life, and fatigue.

Discussion

Iron supplementation administered intravenously in non-anaemic but iron-deficient blood donors could represent an effective strategy to protect blood donors from comorbidities related with iron deficiency and therefore improve blood donor wellbeing. Furthermore, iron supplementation will help to maintain an iron-replete blood donor pool.

Trial registration

EudraCT: 2013-000327-14, Clinical Trials Identifier: NCT01787526. Registered on 6 February 2013.

Electronic supplementary material

The online version of this article (doi:10.1186/s13063-016-1648-y) contains supplementary material, which is available to authorized users.

Effect of Intravenous Iron Supplementation on Iron Stores in Non-Anemic Iron-Deficient Patients with Hereditary Hemorrhagic Telangiectasia

In hereditary hemorrhagic telangiectasia (HHT), frequent episodes of nasal and gastrointestinal bleeding commonly lead to iron-deficiency with or without anemia. In the retrospective study presented here we assessed the iron stores, as determined by analysis of plasma ferritin, during oral and intravenous iron supplementation, respectively, in a population of iron-deficient non-anemic HHT patients who were inadequately iron-repleted by oral supplementation. A switch from oral to intravenous iron supplementation was associated with a significant increase in ferritin in this patient population.

Double red blood cell donors with increased ferritin levels: a descriptive study

BACKGROUND

One of the measures proposed to mitigate iron loss in blood donors is monitoring of their ferritin levels. Occasionally, high ferritin levels are found in monitored donors. We report the results of the clinical and laboratory investigation of 80 double red blood cell (DRBC) donors with high ferritin levels.

STUDY DESIGN AND METHODS

All DRBC donors' ferritin levels were measured during each visit for a donation. Donors with high ferritin levels who agreed to participate underwent a clinical and laboratory evaluation.

RESULTS

A total of 165 of 2757 DRBC donors had at least one high ferritin level. Five were already known to suffer from hemochromatosis. A full investigation was available for 80 other donors. A total of 61 of 80 donors had normalized their ferritin level at the time of their laboratory evaluation. Only 16 donors had high serum iron levels, of whom four had increased saturation index. Genetic analysis gave the following results: C282Y homozygous, two; H63D homozygous, six; C282Y/HC3D double heterozygote, six; C282Y heterozygote, six; H63D heterozygote, 19; and no mutations, 39. None of the other laboratory investigations contributed data explaining the high ferritin levels observed.

CONCLUSION

In most donors with high ferritin levels, the phenomenon was transient, with normal ferritin levels found in follow-up. Less than 10% of these donors had evidence of iron overload. Only eight were homozygous for mutations associated with hemochromatosis. An extensive laboratory investigation by the treating physician should only be recommended in donors with persistently high ferritin levels.

The safety of intravenous iron preparations: systematic review and meta-analysis

OBJECTIVE

To amass all available evidence regarding the safety of intravenous (IV) iron preparations to provide a true balance of efficacy and safety.

METHODS

Systematic review and meta-analysis of all randomized clinical trials comparing IV iron to another comparator. All electronic databases until January 1, 2014, were reviewed. Primary outcome was occurrence of severe adverse events (SAEs). Secondary outcomes included all-cause mortality and other adverse events (AEs). Subgroup analysis was performed on the basis of type of IV iron, comparator, treated condition, and system involved.

RESULTS

A total of 103 trials published between 1965 through 2013 were included. A total of 10,390 patients were treated with IV iron compared with 4044 patients treated with oral iron, 1329 with no iron, 3335 with placebo, and 155 with intramuscular iron. There was no increased risk of SAEs with IV iron (relative risk [RR], 1.04; 95% CI, 0.93-1.17; I(2)=9%). Subgroup analysis revealed a decreased rate of SAEs when IV iron was used to treat heart failure (RR, 0.45; 95% CI, 0.29-0.70; I(2)=0%). Severe infusion reactions were more common with IV iron (RR, 2.47; 95% CI, 1.43-4.28; I(2)=0%). There was no increased risk of infections with IV iron. Gastrointestinal AEs were reduced with IV iron.

CONCLUSION

Intravenous iron therapy is not associated with an increased risk of SAEs or infections. Infusion reactions are more pronounced with IV iron.

Consensus clinical practice guidelines for the diagnosis and treatment of restless legs syndrome/Willis-Ekbom disease during pregnancy and lactation

Restless legs syndrome (RLS)/Willis-Ekbom disease (WED) is common during pregnancy, affecting approximately one in five pregnant women in Western countries. Many report moderate or severe symptoms and negative impact on sleep. There is very little information in the medical literature for practitioners on the management of this condition during pregnancy. Accordingly, a task force was chosen by the International RLS Study Group (IRLSSG) to develop guidelines for the diagnosis and treatment of RLS/WED during pregnancy and lactation. A committee of nine experts in RLS/WED and/or obstetrics developed a set of 12 consensus questions, conducted a literature search, and extensively discussed potential guidelines. Recommendations were approved by the IRLSSG executive committee, reviewed by IRLSSG membership, and approved by the WED Foundation Medical Advisory Board. These guidelines address diagnosis, differential diagnosis, clinical course, and severity assessment of RLS/WED during pregnancy and lactation. Nonpharmacologic approaches, including reassurance, exercise and avoidance of exacerbating factors, are outlined. A rationale for iron supplementation is presented. Medications for RLS/WED are risk/benefit rated for use during pregnancy and lactation. A few are rated "may be considered" when RLS/WED is refractory to more conservative approaches. An algorithm summarizes the recommendations. These guidelines are intended to improve clinical practice and promote further research.

Sleep disorders: A review of the interface between restless legs syndrome and iron metabolism

Restless legs syndrome (RLS) is characterized by unpleasant sensations mainly in the legs. 43% of RLS-associated conditions have also been associated with systemic iron deficiency. The objective of this study was to review in the literature the relationship between iron metabolism and RLS. With an initial search using the keywords combination “Iron Metabolism OR Iron Deficiency AND Restless Legs Syndrome,” 145 articles were screened, and 20 articles were selected. Few studies were found for this review in the period of 2001–2014, however, the correlation between RLS and iron was evident.

Oral or parenteral iron supplementation to reduce deferral, iron deficiency and/or anaemia in blood donors

BACKGROUND

Iron deficiency is a significant cause of deferral in people wishing to donate blood. If iron removed from the body through blood donation is not replaced, then donors may become iron deficient. All donors are screened at each visit for low haemoglobin (Hb) levels. However, some deferred blood donors do not return to donate. Deferred first-time donors are even less likely to return. Interventions that reduce the risk of provoking iron deficiency and anaemia in blood donors will therefore increase the number of blood donations. Currently, iron supplementation for blood donors is not a standard of care in many blood services. A systematic review is required to answer specific questions regarding the efficacy and safety of iron supplementation in blood donors.

OBJECTIVES

To assess the efficacy and safety of iron supplementation to reduce deferral, iron deficiency and/or anaemia in blood donors.

SEARCH METHODS

We ran the search on 18 November 2013. We searched Cochrane Injuries Group Specialised Register, CENTRAL, PubMed, MEDLINE (OvidSP), EMBASE (OvidSP), CINAHL (EBSCO Host) and six other databases. We also searched clinical trials registers and screened guidelines reference lists.

SELECTION CRITERIA

Randomised controlled trials (RCTs) comparing iron supplementation versus placebo or control, oral versus parenteral iron supplementation, iron supplementation versus iron-rich food supplements, and different doses, treatment durations and preparations of iron supplementation in healthy blood donors. Autologous blood donors were excluded.

DATA COLLECTION AND ANALYSIS

We combined data using random-effects meta-analyses. We evaluated heterogeneity using the I(2) statistic; we explored considerable heterogeneity (I(2) > 75%) in subgroup analyses. We carried out sensitivity analyses to assess the impact of trial quality on the results.

MAIN RESULTS

Thirty RCTs (4704 participants) met the eligibility criteria, including 19 comparisons of iron supplementation and placebo or control; one comparison of oral and parenteral iron supplementation; four comparisons of different doses of iron supplementation; one comparison of different treatment durations of iron supplementation; and 12 comparisons of different iron supplementation preparations.Many studies were of low or uncertain methodological quality and therefore at high or uncertain risk of bias. We therefore rated the quality of the evidence for our outcomes as moderate. There was a statistically significant reduction in deferral due to low haemoglobin in donors who received iron supplementation compared with donors who received no iron supplementation, both at the first donation visit after commencement of iron supplementation (risk ratio (RR) 0.34; 95% confidence interval (CI) 0.21 to 0.55; four studies; 1194 participants; P value < 0.0001) and at subsequent donations (RR 0.25; 95% CI 0.15 to 0.41; three studies; 793 participants; P value < 0.00001). Supplementation also resulted in significantly higher haemoglobin levels (mean difference (MD) 2.36 g/L; 95% CI 0.06 to 4.66; eight studies; 847 participants, P value =0.04), and iron stores, including serum ferritin (MD 13.98 ng/mL; 95% CI 8.92 to 19.03; five studies; 640 participants; P value < 0.00001) and transferrin saturation (MD 3.91%; 95% CI 2.02 to 5.80; four studies; 344 participants; P value < 0.0001) prior to further donation. The differences were maintained after subsequent donation(s).Adverse effects were widely reported and were more frequent in donors who received iron supplementation (RR 1.60; 95% CI 1.23 to 2.07; four studies; 1748 participants; P value = 0.0005). Adverse effects included constipation, diarrhoea, nausea, vomiting and taste disturbances, and some participants stopped treatment due to side effects.

AUTHORS' CONCLUSIONS

There is moderate quality evidence that rates of donor deferral due to low haemoglobin are considerably less in those taking iron supplements compared with those without iron supplementation, both at the first donation visit and at subsequent donation. Iron-supplemented donors also show elevated haemoglobin and iron stores. These beneficial effects are balanced by more frequent adverse events in donors who receive iron supplementation than in those who do not; this is likely to limit acceptability and compliance. The long-term effects of iron supplementation without measurement of iron stores are unknown. These considerations are likely to preclude widespread use of iron supplementation by tablets. Blood services may consider targeted use of supplementation in those at greatest risk of iron deficiency, personalised donation intervals and providing dietary advice.

Iron in Restless Legs Syndrome

A link between restless legs syndrome (RLS) and iron has been recognized for several decades. Yet, the precise role that iron or other components of iron metabolism play in bringing about RLS is still a matter of debate. During the last few years, many new pieces of evidence from genetics, pathology, imaging, and clinical studies have surfaced. However, the way this evidence fits into the larger picture of RLS as a disease is not always easily understood. To provide a better understanding of the complex interplay between iron metabolism and RLS and highlight areas that need further elucidation, we systematically and critically review the current literature on the role of iron in RLS pathophysiology and treatment with a special emphasis on genetics, neuropathology, cell and animal models, imaging studies, and therapy.

Iron deficiency in blood donors: a national cross-sectional study

BACKGROUND

Iron deficiency (ID) is an important consequence of blood donation. The epidemiology of this problem in the blood donor population was therefore studied to enable appropriate targeting of potential solutions to donor ID.

STUDY DESIGN AND METHODS

A nationally representative, cluster-based cross-sectional study of Australian blood donors was performed. Donors were eligible for inclusion if they fulfilled criteria for blood donation or were deferred due to low or falling hemoglobin. Ferritin was measured and demographic and donation data were collected.

RESULTS

A total of 3094 blood donors were recruited, of which samples were collected from 3049 donors; 1873 had exclusively donated whole blood (WB only), 242 had exclusively made apheresis donations, and 530 had not donated ("new" donors) in the previous 24 months. The prevalence of ID in new female donors was 12.0% compared with 1.3% in males. The prevalence of ID in female WB-only donors was 26.4%; it increased with donation frequency and decreased with age. The prevalence in male WB-only donors was 6.3% with no evident change with age or donation frequency. The prevalence of ID in apheresis-only donors (females 6.3%; males 2.2%) did not significantly exceed that of new donors nor did it change with donation frequency. Importantly, the risk of ID could not be satisfactorily predicted in an individual donor by his or her anemia status or with predictive modeling incorporating demographic and donation data.

CONCLUSION

ID is especially prevalent in female, premenopausal, frequent WB donors. Strategies to combat ID should be implemented, specifically targeting this group.

Safety and efficacy of intravenous iron therapy in reducing requirement for allogeneic blood transfusion: systematic review and meta-analysis of randomised clinical trials

OBJECTIVES

To evaluate the efficacy and safety of intravenous iron, focusing primarily on its effects on haemoglobin, requirement for transfusion, and risk of infection.

DESIGN

Systematic review and meta-analysis of randomised controlled trials investigating the safety and efficacy of intravenous iron therapy.

DATA SOURCES

Randomised controlled trials from Medline, Embase, and the Cochrane Central Register of Controlled Trials from 1966 to June 2013, with no language restrictions.

ELIGIBILITY CRITERIA FOR SELECTING STUDIES

Eligible trials were randomised controlled trials of intravenous iron compared with either no iron or oral iron. Crossover and observational studies were excluded.

MAIN OUTCOME MEASURES

Change in haemoglobin concentration and risk of allogeneic red blood cell transfusion (efficacy) and risk of infection (safety).

RESULTS

Of the 75 trials meeting the inclusion criteria, 72 studies including 10 605 patients provided quantitative outcome data for meta-analysis. Intravenous iron was associated with an increase in haemoglobin concentration (standardised mean difference 6.5 g/L, 95% confidence interval 5.1 g/L to 7.9 g/L) and a reduced risk of requirement for red blood cell transfusion (risk ratio 0.74, 95% confidence interval 0.62 to 0.88), especially when intravenous iron was used with erythroid stimulating agents (ESAs) or in patients with a lower baseline plasma ferritin concentration. There were no significant interactions between the efficacy of intravenous iron and type or dose administered. Intravenous iron was, however, associated with a significant increase in risk of infection (relative risk 1.33, 95% confidence interval 1.10 to 1.64) compared with oral or no iron supplementation. The results remained similar when only high quality trials were analysed.

CONCLUSIONS

Intravenous iron therapy is effective in increasing haemoglobin concentration and reducing the risk of allogeneic red blood cell transfusion and could have broad applicability to a range of acute care settings. This potential benefit is counterbalanced by a potential increased risk of infection.

Iron for restless legs syndrome

BACKGROUND

Restless legs syndrome (RLS) is a common neurologic syndrome and is associated with iron deficiency in many patients. It is unclear whether iron therapy is effective treatment for RLS.

OBJECTIVES

The objective of this review was to assess the effects of iron supplementation (oral or intravenous) for patients with RLS.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE (Jan 1995 to April 2011); EMBASE (Jan 1995 to April 2011); PsycINFO (Jan 1995 to April 2011); and CINAHL (Jan 1995 to April 2011). Corresponding authors of included trials and additional members of the International Restless Legs Syndrome Study Group were contacted to locate additional published or unpublished trials.

SELECTION CRITERIA

Controlled trials comparing any formulation of iron with placebo, other medications, or no treatment in adults diagnosed with RLS according to expert clinical interview or explicit diagnostic criteria.

DATA COLLECTION AND ANALYSIS

Two review authors extracted data and at least two authors assessed trial quality. We contacted trial authors for missing data.

MAIN RESULTS

Six studies (192 total subjects) were identified and included in this analysis. The quality of trials was variable. Our primary outcome was restlessness or uncomfortable leg sensations, which was quantified using the IRLS severity scale in four trials and another RLS symptom scale in a fifth trial. Combining data from the four trials using the IRLS severity scale, there was no clear benefit from iron therapy (mean difference in IRLS severity scores of -3.79, 95% CI: -7.68 to 0.10, p = 0.06). However, the fifth trial did find iron therapy to be beneficial (median decrease of 3 points in the iron group and no change in the placebo group on a 10 point scale of RLS symptoms, p = 0.01). Quality of life was improved in the iron group relative to placebo in some studies but not others. Changes in periodic limb movements were not different between groups (measured in two studies). Objective sleep quality, subjective sleep quality and daytime functioning were not different between treatment groups in the studies that assessed them. The single study of subjects with end stage renal disease did show a benefit of therapy. Most trials did not require subjects to have co-morbid iron deficiency and several excluded patients with severe anemia. The single study that was limited to iron deficient subjects did not show clear benefit of iron supplementation on RLS symptoms. There was no clear superiority of oral or intravenous delivery of iron. Iron therapy did not result in significantly more side effects than placebo (RR 1.39, 95% CI 0.85 to 2.27).

AUTHORS' CONCLUSIONS

There is insufficient evidence to determine whether iron therapy is beneficial for the treatment of RLS. Further research to determine whether some or all types of RLS patients may benefit from iron therapy, as well as the best route of iron administration, is needed.

Clinical evaluation of iron treatment efficiency among non-anemic but iron-deficient female blood donors: a randomized controlled trial

BACKGROUND

Iron deficiency without anemia is related to adverse symptoms that can be relieved by supplementation. Since a blood donation can induce such an iron deficiency, we investigated the clinical impact of iron treatment after a blood donation.

METHODS

One week after donation, we randomly assigned 154 female donors with iron deficiency without anemia, aged below 50 years, to a four-week oral treatment of ferrous sulfate versus a placebo. The main outcome was the change in the level of fatigue before and after the intervention. Aerobic capacity, mood disorder, quality of life, compliance and adverse events were also evaluated. Hemoglobin and ferritin were used as biological markers.

RESULTS

The effect of the treatment from baseline to four weeks of iron treatment was an increase in hemoglobin and ferritin levels to 5.2 g/L (P < 0.01) and 14.8 ng/mL (P < 0.01), respectively. No significant clinical effect was observed for fatigue (-0.15 points, 95% confidence interval -0.9 points to 0.6 points, P = 0.697) or for other outcomes. Compliance and interruption for side effects was similar in both groups. Additionally, blood donation did not induce overt symptoms of fatigue in spite of the significant biological changes it produces.

CONCLUSIONS

These data are valuable as they enable us to conclude that donors with iron deficiency without anemia after a blood donation would not clinically benefit from iron supplementation.

TRIAL REGISTRATION

ClinicalTrials.gov: NCT00981877.

Adverse events and safety issues in blood donation--a comprehensive review

Although blood donation is generally safe, a variety of risks and complications exist, the most common being iron deficiency, vasovagal reactions and citrate-related events. In the last decades, extensive efforts have significantly improved recipient and product safety, but there is still great potential to optimise donor care. Many therapies in modern medicine depend on the prompt availability of blood products, therefore it is crucial to maintain a motivated and healthy donor pool in view of a limited number of healthy volunteers willing and able to give blood or blood components. We present a comprehensive review on adverse events addressing all types of blood donation including whole blood, plasma, platelet, peripheral blood stem cell, leucocyte and bone marrow donation. In addition, we outline strategies for the prevention and treatment of these events and give a blueprint for future research in this field.