Anemia management in patients with chronic renal insufficiency

Risk of Nonarteritic Anterior Ischemic Optic Neuropathy Following End-Stage Renal Disease

To investigate the risk of nonarteritic anterior ischemic optic neuropathy (NAION) following end-stage renal disease (ESRD).A retrospective, nationwide, matched cohort study.ESRD patients identified by the International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) code 585.The study cohort included 93,804 ESRD patients registered with the Taiwan National Health Insurance Research Database between January 2000 and December 2009. An age- and sex-matched control group comprised 93,804 patients (case:control = 1:1) selected from the Taiwan Longitudinal Health Insurance Database 2000. Information for each patient was collected from the index date until December 2011. The incidence and risk of NAION were compared between the ESRD and control groups. The adjusted hazard ratio (HR) for NAION after adjustment for potential confounders was obtained by a Cox proportional hazard regression analysis. A Kaplan-Meier analysis was used to calculate the cumulative incidence rate of NAION.The incidence of NAION following ESRD.In total, 133 ESRD patients (0.14%) and 51 controls (0.05%) had NAION (P < 0.001) during the follow-up period, leading to a significantly elevated risk of NAION in the ESRD patients compared with the controls (incidence rate ratio = 3.14, 95% confidence interval [CI] = 2.11-4.67). After adjustment for potential confounders including diabetes mellitus, hypertension, hypotension, hyperlipidemia, and 2-way interaction terms between any 2 factors, ESRD patients were 3.12 times more likely to develop NAION than non-ESRD patients in the full cohort (adjusted HR = 3.12, 95% CI = 2.10-4.64). Additionally, patients with hypertension and hyperlipidemia showed higher incidence rates of NAION in the ESRD group compared with the controls: 2.31 (95% CI = 1.40-3.82) for hypertension and 2.72 (95% CI = 1.14-6.50) for hyperlipidemia.ESRD increased the risk of NAION, which is an interdisciplinary emergency. Close collaboration between nephrologists and ophthalmologists is important in NAION management following ESRD to prevent fellow eye involvement.

Renoprotection, renin inhibition, and blood pressure control: the impact of aliskiren on integrated blood pressure control

Hypertension (HTN) is an important factor in progressive loss of renal function. The kidney can be both a contributor to and a target of HTN. The functional integrity of the kidney is vital for the maintenance of cardiovascular homeostasis. Chronic activation of the renin system causes HTN and, ultimately, end-organ damage. Direct renin inhibitors (DRIs) inhibit plasma renin activity (PRA), thereby preventing the conversion of angiotensinogen to angiotensin I; consequently, the levels of both Ang I and Ang II are reduced. There is no compensatory increase in PRA activity with DRIs as seen with angiotensin-converting enzyme inhibitors (ACEIs) or angiotensin receptor blockers (ARBs). There are reasons to speculate that renin inhibition might prove to be a superior strategy for blocking the renin-angiotensin-aldosterone system compared with ACEIs or ARBs. Evidence for the efficacy of aliskiren (a DRI) is considered to be relatively strong, based on published, short-term, double-blind, randomized, controlled trials showing that aliskiren is as effective as other antihypertensive agents in reducing blood pressure (BP), with no rebound effects on BP after treatment withdrawal. When combined with diuretics, fully additive BP reduction is seen. When given with an ACEI or ARB, aliskiren produces significant additional BP reduction indicative of complimentary pharmacology and more complete renin-angiotensin system blockade.

Erythropoietic stress and anemia in diabetes mellitus

Anemia is one of the world's most common preventable conditions, yet it is often overlooked, especially in people with diabetes mellitus. Diabetes-related chronic hyperglycemia can lead to a hypoxic environment in the renal interstitium, which results in impaired production of erythropoietin by the peritubular fibroblasts and subsequent anemia. Anemia in patients with diabetes mellitus might contribute to the pathogenesis and progression of cardiovascular disease and aggravate diabetic nephropathy and retinopathy. Anemia occurs earlier in patients with diabetic renal disease than in nondiabetic individuals with chronic kidney disease. Although erythropoietin has been used to treat renal anemia for nearly two decades, debate persists over the optimal target hemoglobin level. Most guidelines recommend that hemoglobin levels be maintained between 105g/l and 125g/l. The suggested role of anemia correction--to prevent the progression of left ventricular hypertrophy in patients with diabetes mellitus--is yet to be established. However, an emphasis on regular screening for anemia, alongside that for other diabetes-related complications, might help to delay the progression of vascular complications in these patients.

Outpatient management of chronic kidney disease: proteinuria, anemia and bone disease as therapeutic targets

There is increasing emphasis on chronic kidney disease (CKD), owing to its prevalence and its association with cardiovascular risk. Important issues concerning treatment of CKD are delaying its progression, improving patients' quality of life, and decreasing related mortality. These issues can be addressed with certain therapeutic options, targeting proteinuria, anemia, and secondary hyperparathyroidism. The management options and possible benefits related to treatment of these complications of CKD are reviewed.

Association of anemia correction with health related quality of life in patients not on dialysis

OBJECTIVE

This was an open-label study to asses the association of changes in hemoglobin with changes in health related quality of life (HRQOL) in patients treated with darbepoetin alfa.

METHODS

Originally, 81 chronic kidney disease (CKD) patients not on dialysis and naïve to erythropoiesis stimulating agents (ESA) were randomly assigned into two open-label groups (3 : 1). As a majority of control group patients opted out of control status, this study reports on the single arm study analysis that was performed on the 48 patients who received the drug through week 16. Sixty-two patients received once-weekly darbepoetin alfa in addition to conservative management for CKD. Instruments that measured general (SF-36, FACTanemia, FACT-fatigue, ADL and IADL) and disease specific (KDQOL) HRQOL domains were administered at baseline and after 8, 16, and 24 weeks.

RESULTS

Compared to baseline values, mean HRQOL subscales were significantly improved in the treatment group at 16 weeks (p < 0.05 for SF-36 physical function; p < 0.001 for SF-36 vitality, FACT anemia and FACT fatigue scales). At week 16, the SF-36 mean increase for 48 treatment patients in the Vitality Subscale Score was 14.9 (SD 3.2) and the mean increase in the KDQOL Burden of Kidney Disease Subscale was 5.5 (SD 3.3). Multivariate regression analysis demonstrated a statistically significant association (p < 0.05) between hemoglobin levels and higher HRQOL scores on several physical function, energy and fatigue scales.

CONCLUSION

Improvements in hemoglobin in CKD patients not on dialysis were associated with statistically significant (p < 0.05), clinically meaningful (> 5 points) HRQOL improvements on scales measuring physical activity, vitality and fatigue. Our study did not show an association between increased hemoglobin levels and other aspects of HRQOL, such as those relating to emotional status, sexual activity or cognition. The interpretation of our results is limited by the lack of a control arm to assess whether conservative therapy for CKD, in the absence of ESA administration, would have a comparable effect on patients' HRQOL scores. Further research needs to examine whether other aspects of HRQOL improve with anemia treatment, in the same way as those aspects of HRQOL more closely related to physical activity and fatigue.

Parenteral iron treatment induces MCP-1 accumulation in plasma, normal kidneys, and in experimental nephropathy

INTRODUCTION

Monocyte chemoattractant protein-1 (MCP-1) promotes renal inflammation, thereby contributing to acute and chronic nephropathies. Its production is stimulated by oxidative stress. Thus, this study tested whether pro-oxidant iron/carbohydrate complexes, used to treat iron deficiency, induce MCP-1 in renal/extrarenal tissues, in plasma, and in the setting of experimental nephropathy.

METHODS

CD-1 mice received 2 mg of intravenous iron [complexed with dextran (iron dextran), sucrose (iron sucrose), or gluconate (iron gluconate)]. Renal MCP-1 and/or its mRNA were measured 3 hours to 7 days post-iron injection. Iron effects on liver, lung, spleen, and heart MCP-1 mRNA, and on peritoneal lavage fluid MCP-1 concentrations were assessed. Iron pretreatment effects on MCP-1 levels in unilaterally obstructed kidneys vs. contralateral kidneys were determined. Finally, iron gluconate's influence on proximal tubule [human kidney-2 (HK-2)] cell MCP-1 levels was assessed.

RESULTS

Iron sucrose (the primary test agent) markedly increased plasma and renal MCP-1 levels. It also induced multiorgan MCP-1 mRNA increments (liver > spleen > kidney > lung > heart). Iron gluconate was more potent than iron sucrose; conversely, iron dextran had no discernible effect. The iron dextran and iron sucrose-induced renal MCP-1 mRNA increments ( approximately 4x) were persistent, lasting for at least 3 to 7 days. Iron gluconate raised MCP-1 levels in peritoneal lavage fluid. It also doubled MCP-1 in unilaterally obstructed kidneys (ureteral ligation) without altering contralateral (control kidney) MCP-1 content. Iron gluconate raised HK-2 cell MCP-1, implying a direct proximal tubule effect.

CONCLUSION

Iron sucrose and iron gluconate (but not iron dextran) can induce MCP-1 generation in renal and extrarenal tissues, possibly via transcriptional events. This may dramatically impact renal disease-induced MCP-1 increments. Finally, iron can increase peritoneal lavage fluid MCP-1 levels. Whether the above changes have implications for renal disease progression, and/or for peritoneal inflammation/peritoneal dialysis efficiency, are issues which may need to be addressed.

Sex, haemoglobin and kidney disease: new perspectives

Anaemia is recognized as a common complication of chronic kidney disease with significant associated morbidity and mortality. Published data document the negative impact of anaemia on cardiovascular disease outcomes, progression of chronic kidney disease (CKD), hospitalizations, rehabilitation and quality of life, among others. Gender differences have been identified in many of these areas as well as, and importantly, in cardiovascular and chronic kidney disease outcomes. Female gender is associated with lower risk of cardiovascular morbidity and mortality as well as slower progression of chronic kidney disease. Interestingly, there are some well-described physiological adaptations to anaemia in women, which include shifting of the haemoglobin oxygen dissociation curve to reduce oxygen affinity secondary to higher levels of 2,3-diphosphoglycerate. However, the complex physiology underlying the impact of anaemia or gender on patients with chronic kidney disease is not well-characterized to date. Furthermore, there has been little examination of the potential interaction between anaemia and gender on cardiac or kidney outcomes. In this paper, we review the documented impact of anaemia and gender on outcomes, and explore the interaction of anaemia and gender in patients with CKD. We also present data that describe the potential importance of considering gender when targeting specific levels of haemoglobin. The value of a new perspective on haemoglobin and gender in kidney disease is important from both a physiological and an economical perspective.

Sodium ferric gluconate complex therapy in anemic children on hemodialysis

Pediatric patients with end-stage renal disease undergoing hemodialysis (HD) frequently develop anemia. Administration of recombinant human erythropoietin (rHuEPO) is effective in managing this anemia, although the additional demand for iron often results in iron deficiency. In adult patients undergoing HD, intravenous (IV) iron administration is known to replenish iron stores more effectively than oral iron administration. Nevertheless, IV iron supplementation is underutilized in pediatric patients, possibly because of unproved safety in this population. This international, multicenter study investigated the safety and efficacy of two dosing regimens (1.5 mg kg(-1) and 3.0 mg kg(-1)) of sodium ferric gluconate complex (SFGC) therapy, during eight consecutive HD sessions, in iron-deficient pediatric HD patients receiving concomitant rHuEPO therapy. Safety was evaluated in 66 patients and efficacy was evaluated in 56 patients. Significant increases from baseline were observed in both treatment groups 2 and 4 weeks after cessation of SFGC dosing for mean hemoglobin, hematocrit, transferrin saturation, serum ferritin, and reticulocyte hemoglobin content. Efficacy and safety profiles were comparable for 1.5 mg kg(-1) and 3.0 mg kg(-1) SFGC with no unexpected adverse events with either dose. Administration of SFGC was safe and efficacious in the pediatric HD population. Given the equivalent efficacy of the two doses, an initial dosing regimen of 1.5 mg kg(-1) is recommended for pediatric HD patients.

Elevated cardiac troponin T in hemodialysis patients receiving more intravenous iron sucrose

Elevated cardiac troponin T (cTnT) has been associated with shorter survival in hemodialysis patients. Moreover, intravenous (IV) iron treatment has been held responsible for oxidative stress and accelerated atherosclerosis in these patients. In the present study, we investigated the relationship between cTnT concentration, IV iron treatment, and parameters of iron status. In addition, parameters of oxidative stress, inflammation, and atherosclerosis were evaluated. Predialysis blood samples of 78 chronic hemodialysis patients were analyzed for cTnT, malondialdehyde, creatine kinase (CK), and CK-isoenzyme MB (CK-MB). In addition, the mean value of predialysis serum samples collected during the last year, were considered for homocysteine, ferritin, iron, iron binding capacity, blood cell counts, blood urea nitrogen, creatinine, albumin, erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), calcium, phosphate, iPTH, cholesterol, and triglyceride. The quantity of IV iron sucrose administered during the last two years was counted from the patients' files. Echocardiography, all events related to ischemic heart disease, and urine volume were also recorded. Elevated cTnT levels (> or =0.10 ng/mL) were found in 18 patients (23.1%). The amount of iron administered was 2264+/-1871 mg with a range 0-7000 mg. Patients with elevated cTnT levels received more IV iron than those with normal cTnT (3692+/-1771 vs. 1761+/-1595 mg, p<0.001). The serum ferritin level was higher in patients with elevated cTnT (median levels; 477 vs. 288 ng/mL; P<0.05). Patients with elevated cTnT were longer on dialysis compared to those with normal levels (median times; 35.5 vs. 15 months, P<0.01) and regression analysis identified the amount of administered iron as an independent factor for elevated cTnT (P<0.01). Intravenous iron treatment and high ferritin concentration are related to high cTnT level, which has previously been incriminated as a survival marker in hemodialysis patients.

Parenteral iron compounds sensitize mice to injury-initiated TNF-alpha mRNA production and TNF-alpha release

Intravenous Fe is widely used to treat anemia in renal disease patients. However, concerns of potential Fe toxicity exist. To more fully define its spectrum, this study tested Fe's impact on systemic inflammation following either endotoxemia or the induction of direct tissue damage (glycerol-mediated rhabdomyolysis). The inflammatory response was gauged by tissue TNF-alpha message expression and plasma TNF-alpha levels. CD-1 mice received either intravenous Fe sucrose, -gluconate, or -dextran (FeS, FeG, or FeD, respectively; 2 mg), followed by either endotoxin (LPS) or glycerol injection 0-48 h later. Plasma TNF-alpha was assessed by ELISA 2-3 h after the LPS or glycerol challenge. TNF-alpha mRNA expression (RT-PCR) was measured in the kidney, heart, liver, lung, and spleen with Fe +/- LPS treatment. Finally, the relative impacts of intramuscular vs. intravenous Fe and of glutathione (GSH) on Fe/LPS- induced TNF-alpha generation were assessed. Each Fe preparation significantly enhanced LPS- or muscle injury-mediated TNF-alpha generation. This effect was observed for at least 48 h post-Fe injection, a time at which plasma iron levels were increased by levels insufficient to fully saturate transferrin. Fe did not independently increase plasma TNF-alpha or tissue mRNA. However, it potentiated postinjury-induced TNF-alpha mRNA increments and did so in an organ-specific fashion (kidney, heart, and lung; but not in liver or spleen). Intramuscular administration, but not GSH treatment, negated Fe's ability to synergize LPS-mediated TNF-alpha release. We conclude 1) intravenous Fe can enhance TNF-alpha generation during LPS- or glycerol-induced tissue damage; 2) increased TNF-alpha gene transcription in the kidney, heart, and lung may contribute to this result; and 3) intramuscular administration, but not GSH, might potentially mitigate some of Fe's systemic toxic effects.

Translating research findings of chronic kidney disease management to clinical practice: Challenges and opportunities

Chronic Kidney disease (CKD) has been identified as a public health epidemic, fueled in part by improved outcomes of both diabetic and cardiac patient populations, as well as by the increasing recognition that it is possible to identify CKD at earlier stages. The estimated 8 to 10 million Americans that have CKD, with its concomitant morbidity and mortality, have the potential to overwhelm the current system of specialty practice medicine and health care resources. How can clinicians, clinician scientists, and health care administrators translate research findings into clinical practice in an effective manner to improve the care of this burgeoning patient group? The challenge of translating research into clinical care requires identification of that which we do and do not know, communication of knowledge between those who do and do not know, and efficient collection of information for systematic evaluation. This article will describe the challenges of translating current research findings into clinical practice. There is a need to identify the complexity of CKD disease processes and issues associated with delivery of care and to describe the difficulties in the dissemination of new knowledge to physicians. Because of the propensity of CKD to affect identifiable groups of patients, we will discuss the potential challenges of these strategies given the racial, ethnic, and cultural diversity in North America. A potential solution to these challenges is a new paradigm of "process-based medicine" that integrates clinical and basic science research findings with multidisciplinary and shared care models of health care delivery. In this context, attention to advances in information technology, the cognitive processes that underlie physician learning, and the findings of outcome research may ensure true integration of clinical research and clinical practice.

The effects of iron dextran on the oxidative stress in cardiovascular tissues of rats with chronic renal failure

BACKGROUND

Redox-active iron can promote oxidative stress and tissue injury by catalyzing hydroxyl radical generation and lipid peroxidation. Intravenous iron preparations are routinely administered in conjunction with erythropoietin to treat anemia in patients with chronic renal failure (CRF), a condition that is marked by oxidative stress and inflammation. This treatment frequently elevates iron burden, which can potentially intensify oxidative stress and, thus, cardiovascular disease in this population.

METHODS

We studied renal function and oxidative stress parameters in the cardiovascular tissues of CRF (5/6 nephrectomized) and sham-operated control rats 3 months after a single intravenous infusion of iron dextran (500 mg/kg).

RESULTS

Arterial pressure was equally elevated and creatinine clearance was equally reduced in both iron-treated and -untreated CRF groups. Iron administration significantly raised the blood hemoglobin, serum iron concentration, and transferrin saturation in both CRF and control groups. Iron administration resulted in a significant rise in plasma concentration of lipid peroxidation product, malondialdehyde in the CRF rats, and an insignificant rise in the control group. Plasma oxidized low-density lipoprotein (LDL) concentration was increased in the CRF groups, and was not affected by iron administrations. Iron administration raised nitrotyrosine abundance in the aorta of CRF but not in the control group. Left ventricular tissue abundance of p22(phox) subunit of NAD(P)H oxidase was elevated in CRF group and was not affected, whereas p67(phox) subunit abundance was raised by prior iron administration. Iron administration insignificantly lowered aorta p22(phox), but had no effect on p67(phox) subunit abundance in the treated CRF group. Previous iron administration significantly lowered superoxide dismutase and catalase abundance in the aorta and glutathione peroxidase in the left ventricle of CRF animals, but did not significantly change these parameters in the iron-treated control animals.

CONCLUSION

A single intravenous injection of iron dextran increased oxidative stress in the cardiovascular tissues in the CRF group, but not the control rats, pointing to heightened susceptibility to iron-mediated toxicity in CRF. However, administration of iron dextran did not adversely affect kidney function, and favorably affected hemoglobin concentration in rats with CRF induced by renal mass reduction. Further studies are needed to explore the effects of other parenteral iron preparations, repeated intravenous iron administration, and presence of comorbid conditions such as diabetes.

Chronic Renal Insufficiency and Cardiovascular Events in the Elderly: Findings From the Cardiovascular Health Study

In the Cardiovascular Health Study, the authors sought to evaluate the impact of chronic renal insufficiency (CRI) on cardiovascular risk status and outcomes in a representative sample of community-dwelling elderly adults. Defined as a serum creatinine level > or =1.3 mg/dL in women and > or =1.5 mg/dL in men, CRI was present in 647 (11%) of 5808 participants. At baseline, the prevalence of clinical or subclinical cardiovascular disease was 64% in participants with CRI and 43% in those without CRI (odds ratio, 2.34; 95% confidence interval, 1.96-2.80). The incidence of cardiovascular disease events during follow-up was 3% per year in participants with creatinine levels <1.10 mg/dL and increased steadily to reach 7% per year in those with creatinine > or =1.70 mg/dL. Among the possible mediators for the association between CRI and cardiovascular morbidity are inflammatory (C-reactive protein, fibrinogen, and interleukin-6) and hemostatic (factor VII, factor VIII, plasmin-antiplasmin product, and D-dimer) biomarkers, all of which were significantly elevated in Cardiovascular Health Study participants with CRI. Future studies should evaluate the contribution of novel and traditional cardiovascular risk factors to the cardiovascular risk of elderly persons with CRI. The identification of CRI in the elderly and the use of cardiovascular prevention therapies represent a major opportunity to reduce their burden of cardiovascular morbidity.

Morbidity and mortality in children with anemia at initiation of dialysis

Studies in adult dialysis patients have identified anemia as a risk factor for patient morbidity and mortality. Limited comparable outcome data are available from children. We used the database from the North American Pediatric Renal Transplant Cooperative Study (NAPRTCS) to identify patients <18 years of age who initiated dialysis (hemodialysis and peritoneal dialysis) between 1992 and 2001 with no prior history of dialysis or transplantation. A Cox proportional hazards model was used to evaluate the association between anemia (hematocrit <33%) at 30 days post initiation of dialysis and patient mortality. The association between anemia and prolonged hospitalization was also evaluated. Of the 1,942 patients (male 56%), 68% were anemic on day 30. One hundred and seventy-one patient deaths were reported over the 9-year observation period. The multivariate analysis demonstrated anemia to be associated with a 52% higher risk of death (adjusted relative risk 1.52, 95% confidence interval 1.03-2.26, P=0.037). Cardiopulmonary disease was the primary reported cause of death associated with anemia, accounting for 22% of cases. The presence of anemia was also associated with an increased risk for prolonged hospitalization, irrespective of dialysis modality. In conclusion, the presence of anemia 1 month after initiation of dialysis iis associated with an increased risk of prolonged hospitalization and death in pediatric patients. Further studies should ascertain whether anemia per se increases the risk of death or whether it is a marker for other conditions that shorten patient survival, such as chronic inflammation or recurrent infection.

Chronic kidney disease: issues and establishing programs and clinics for improved patient outcomes

The spectrum of chronic kidney disease (CKD) extends from the point at which there is slight kidney damage, but normal function, to the point at which patients require either a renal transplant or renal replacement therapy to survive. Epidemiological studies suggest there are approximately 20,000,000 patients with various stages of CKD. These patients have many comorbidities, including cardiovascular disease, hypertension, diabetes, anemia, nutritional and metabolic derangements, and fluid overload. Unfortunately, evidence shows that current CKD care in the United States is suboptimal, and late referral to a nephrologist is often the rule and not the exception. Roles of primary care physicians (PCPs) and nephrologists in the care of patients with CKD remain undefined. Several studies have suggested that care provided by multidisciplinary nephrology teams can improve patient outcomes. Currently, there are published evidence-based clinical practice guidelines for anemia management, nutritional therapy, and vascular access placement, with other CKD guidelines under development. The intent of this review includes providing compelling evidence for earlier screening, identification, and management of patients with CKD; showing that current CKD care is suboptimal; encouraging the development of multidisciplinary teams that provide collaborative care to patients with CKD, suggesting roles for PCPs and nephrologists in the care of these patients; describing CKD initiatives from national organizations; and providing a comprehensive checklist that can guide the development of CKD clinics and programs.

Molecular profiling of anemia in acute renal allograft rejection using DNA microarrays

Compromised renal function after renal allograft transplantation often results in anemia in the recipient. Molecular mechanisms leading to anemia during acute rejection are not fully understood; inadequate erythropoietin production and iron deficiency have been reported to be the main contributors. To increase our understanding of the molecular events underlying anemia in acute rejection, we analyzed the gene expression profiles of peripheral blood lymphocytes (PBL) from four pediatric renal allograft recipients with acute rejection and concurrent anemia, using DNA microarrays containing 9000 human cDNA clones (representing 7469 unique genes). In these anemic rejecting patients, an 'erythropoiesis cluster' of 11 down-regulated genes was identified, involved in hemoglobin transcription and synthesis, iron and folate binding and transport. Additionally, some alloimmune response genes were simultaneously down-regulated. An independent data set of 36 PBL samples, some with acute rejection and some with concurrence of acute rejection and anemia, were analyzed to support a possible association between acute rejection and anemia. In conclusion, analysis using DNA microarrays has identified a cluster of genes related to hemoglobin synthesis and/or erythropoeisis that was altered in kidneys with renal allograft rejection compared with normal kidneys. The possible relationship between alterations in the expression of this cluster, reduced renal function, the alloimmune process itself, and other influences on the renal transplant awaits further analysis.

Issues related to iron replacement in chronic kidney disease

Recent epidemiologic studies show that iron deficiency occurs in the vast majority of patients with chronic kidney disease (CKD). In patients with CKD, increased iron losses and, to a lesser extent, poor oral absorption, can lead to iron-deficiency anemia. Correction of iron-deficiency anemia is preferable by the oral route, however, data on oral iron use are limited in this population. In CKD patients, parenteral iron administered with recombinant human erythropoietin (rHuEpo), is the best potential option for the correction of anemia. Nondextran iron preparations are preferable because of a reduced incidence of serious adverse events. Parenteral iron in CKD patients may not be entirely innocuous and, although commonly used, have not received Food and Drug Administration approval for use in this patient population. Exposure to intravenous (IV) iron may lead to oxidative stress, renal injury, infection, cardiovascular disease, and osteomalacia. Studies are needed to confirm the existence and magnitude of these complications. The current data suggest that the overall risk-benefit ratio favors use of IV iron when compared with untreated or partially treated iron-deficiency anemia.

Safety and efficacy of sodium ferric gluconate complex in patients with chronic kidney disease

BACKGROUND

We hypothesized that intravenous iron will improve hemoglobin (Hgb) concentrations in anemic patients with chronic kidney disease (CKD), and the response would be greater if the underlying erythropoietin deficiency also was treated.

METHODS

Charts of 58 CKD veterans (glomerular filtration rate < 80 mL/min) administered at least 125 mg of sodium ferric gluconate complex in sucrose (SFGC) during a period of 1 year for the primary outcome of an increase in Hgb level by at least 0.5 g/dL were reviewed.

RESULTS

Mean Hgb level at baseline was 10.5 +/- 1.4 (SD) g/dL (105 +/- 14 g/L) in the 30 patients administered recombinant human erythropoietin (rHuEPO) plus SFGC and 10.1 +/- 1.3 g/dL (101 +/- 13 g/L) in the 28 patients administered SFGC alone (P = not significant). The primary event occurred in 83% of the rHuEPO-plus-SFGC group at 31 days compared with 60% at 62 days in the group administered SFGC alone (P = 0.037, Cox F test). In patients administered SFGC alone, mean maximal Hgb level was 11.4 +/- 0.9 g/dL (114 +/- 9 g/L) in contrast to 12.4 +/- 1.7 g/dL (124 +/- 17 g/L) in the combination group, which remained significantly different even after adjustment for biologically important covariates (P = 0.01, analysis of covariance). Of the 240 doses of SFGC administered for which infusion records were available, 237 doses were well tolerated; three hypotensive episodes occurred in 2 patients, which did not result in discontinuation of the drug in either case.

CONCLUSION

Correction of anemia with parenteral iron alone suggests a high prevalence of iron deficiency in patients with CKD. Treatment of concomitant iron deficiency with SFGC was well tolerated in patients with CKD and appears to optimize management of anemia.

Epidemiology of anemia associated with chronic renal insufficiency

Several recently published reports have advanced our understanding of the epidemiology of anemia associated with chronic renal insufficiency. Anemia is commonly observed among subjects with chronic renal insufficiency. In comparison with subjects with preserved renal function, a significant decrease in hemoglobin could be detected in subjects with more modest degrees of renal insufficiency than was previously realized. Some of this undoubtedly reflects a decrease in renal production of erythropoietin, but these subjects may also suffer concomitant 'anemia of chronic disease'. Anemia is more likely not only among those with worse renal insufficiency, but also among black subjects, those with relative iron deficiency and those with lower serum albumin. Compared with those with preserved renal function, a significant decrease in hemoglobin could be detected in men at higher estimated creatinine clearance levels than in women; and at any given creatinine clearance, the decrease in hemoglobin is greater in men than in women. In the US, 800000 adults were estimated to suffer chronic renal insufficiency associated anemia, defined as hemoglobin level below 11 g/dl. As detailed in the present review, several methodological issues should be kept in mind when interpreting the literature. Further studies are needed to define the clinical implications of this common condition and to determine the most appropriate therapeutic response.

Systemic complications of chronic kidney disease. Pinpointing clinical manifestations and best management

The kidney plays a critical role in the maintenance of homeostasis. As kidney function diminishes, excretory, regulatory, and endocrine function is lost, and complications develop in essentially every organ system. Kidney failure is the last stage in the continuum of progressive CKD. Management of the complications associated with CKD mainly includes dietary counseling, adequate control of volume and blood pressure, and use of phosphate binders, calcitriol (Calcijex, Rocaltrol), and erythropoietin. Many of these complications can be prevented or attenuated with optimal CKD care, which involves early detection of progressive kidney disease, interventions to retard its progression, prevention of uremic complications, attenuation of comorbid conditions, adequate preparation for kidney replacement therapy, and timely initiation of dialysis (figure 2). Closer attention to CKD care is likely to be the key to improved outcomes among patients with kidney failure.

Optimizing medical management of patients with pre-end-stage renal disease

Patients with end-stage renal disease have reduced quality of life, high levels of morbidity, and an annual mortality of about 22%. Because the high morbidity and mortality of dialysis patients might be reduced substantially if patients were healthier at the time of initiating renal replacement therapy, this article will present treatment recommendations designed to retard the progression of chronic renal disease, to optimize the medical management of comorbid medical conditions, such as cardiovascular disease, diabetes, and lipid disorders, and to reduce the complications of renal insufficiency, including hypertension, anemia, hyperparathyroidism, and malnutrition. Given the lack of prospective clinical studies in this area, these recommendations are derived from consensus standards for managing dialysis patients or patients with cardiovascular disease, hypertension, diabetes, and lipid disorders, and from expert opinion derived from laboratory investigations of pathophysiology and relevant experimental disease models.

Trends in anemia at initiation of dialysis in the United States

BACKGROUND

Anemia almost invariably develops in patients with chronic renal insufficiency (CRI) and is associated with a wide range of complications. The anemia of CRI can be effectively treated with recombinant human erythropoietin (rHuEPO). Recent studies suggest that the management of anemia of CRI is suboptimal in the United States.

METHODS

We examined the trends in hematocrit and rHuEPO use among all patients who started chronic dialysis therapy between April 1, 1995, and December 31, 1999, from the End-stage Renal Disease Medical Evidence Form 2728 submitted to the Health Care Financing Administration of the United States. Follow-up data containing hematocrit levels after initiation were obtained from the Medicare Part A institutional outpatient dialysis provider claims for 1990 to 1998 prevalent patients.

RESULTS

From June 1995 to June 1999, the mean hematocrit at initiation of dialysis increased from 28.1 to 29.3%. Likewise, the annual percentage of patients receiving pre-dialysis rHuEPO increased from 21.8 to 28.1%. Patients receiving predialysis rHuEPO had a higher mean hematocrit than patients without predialysis rHuEPO. The annual percentage of patients with hematocrit <24% fell 6.6% and the percentage with hematocrit > or =30% increased 9.2%. The trend toward higher hematocrit levels has been consistent across all age, gender, and race categories. Older patients, males, whites, and those who selected peritoneal dialysis had higher hematocrit levels than their counterparts. There were significant geographic differences in the prevalence of predialysis rHuEPO use.

CONCLUSION

There has been a slight improvement in the management of anemia of CRI in the United States. However, a considerable fraction of patients still have hematocrit levels that are significantly lower than the currently recommended target. Furthermore, improvement in the management of anemia could result in improved clinical outcomes among patients with CRI.