Effect of improvement in anemia on electroneurophysiological markers (P300) of cognitive dysfunction in chronic kidney disease

Who should make the decision for renal replacement therapy?

INTRODUCTION

In this study, we aimed to evaluate cognitive functions in Stage 4 and 5 CKD patients using the Montreal Cognitive Assessment (MoCA) Scale, which objectively assesses cognitive dysfunction and various cognitive functions, and to compare them with a control group with normal kidney functions.

METHODS

All participants in our case-control study were administered the Montreal Cognitive Assessment (MoCA) Test, and total scores, subscale scores, and the presence of cognitive dysfunction were recorded.

RESULTS

When the groups were compared in terms of cognitive dysfunction (CD), 12.9% of the control group and 37.1% of the case group were found to have CD, which was statistically significant. When the groups were compared in terms of data and scale scores, the visual construction subscale score, naming, delayed recall subscale score, and total MoCA score were found to be significantly lower in the case group compared to the control group.

CONCLUSION

Our study is the first to use the MoCA test with the correct reference range. The significant impairment observed in the cognitive functions of patients with advanced-stage CKD in our study suggests that the decision for renal replacement therapy should not be made by the patient alone, as it may be incorrect.

Efficacy of erythropoietin as a neuroprotective agent in CKD-associated cognitive dysfunction: A literature systematic review

Patients with chronic kidney disease (CKD) often experience mild cognitive impairment and other neurocognitive disorders. Studies have shown that erythropoietin (EPO) and its receptor have neuroprotective effects in cell and animal models of nervous system disorders. Recombinant human EPO (rHuEPO), commonly used to treat anemia in CKD patients, could be a neuroprotective agent. In this systematic review, we aimed to assess the published studies investigating the cognitive benefits of rHuEPO treatment in individuals with reduced kidney function. We comprehensively searched Pubmed, Cochrane Library, Scopus, and Web of Science databases from 1990 to 2023. After selection, 24 studies were analyzed, considering study design, sample size, participant characteristics, intervention, and main findings. The collective results of these studies in CKD patients indicated that rHuEPO enhances brain function, improves performance on neuropsychological tests, and positively affects electroencephalography measurements. These findings suggest that rHuEPO could be a promising neuroprotective agent for managing CKD-related cognitive impairment.

Cognitive Impairment and Brain Atrophy in Patients with Chronic Kidney Disease

In Japan, the aging of the population is rapidly accelerating, with an increase in patients with chronic kidney disease (CKD) and those undergoing dialysis. As a result, the number of individuals with cognitive impairment (CI) is rising, and addressing this issue has become an urgent problem. A notable feature of dementia in CKD patients is the high frequency of vascular dementia, making its prevention through the management of classical risk factors such as hypertension, diabetes mellitus, dyslipidemia, smoking, etc., associated with atherosclerosis and arteriosclerosis. Other effective measures, including the use of renin-angiotensin system inhibitors, addressing anemia, exercise therapy, and lifestyle improvements, have been reported. The incidence and progression of CI may also be influenced by the type of kidney replacement therapy, with reports suggesting that long-duration dialysis, low-temperature hemodialysis, peritoneal dialysis, and kidney transplantation can have a preferable effect on the preservation of cognitive function. In conclusion, patients with CKD are at a higher risk of developing CI, with brain atrophy being a contributing factor. Despite the identification of various preventive measures, the evidence substantiating their efficacy remains limited across all studies. Future expectations lie in large-scale randomized controlled trials.

A longitudinal analysis of the effect of anemia on executive functions in children with mild to moderate chronic kidney disease

BACKGROUND

Children with chronic kidney disease (CKD) are at risk for cognitive dysfunction. The aim of this study was to investigate associations between executive functions (EF), anemia, and iron deficiency.

METHODS

A total of 688 children > 6 years of age enrolled in the Chronic Kidney Disease in Children (CKiD) study who underwent evaluation for EF were included. Hemoglobin (Hgb) was characterized as low (1st-5th percentile) or very low (< 1st percentile) compared to normative values for age, sex, and race irrespective of erythropoiesis-stimulating agent (ESA) usage. Longitudinal analysis was conducted using consecutive visit pairs, with anemia status defined as new onset, resolved, or persistent. Linear mixed models with random intercept were used and adjusted for key covariates.

RESULTS

Anemia was present in 41% of children, and median Hgb was 11.8 gm/dl. New onset anemia was associated with lower digit span total score (- 0.75, 95% CI - 1.36, - 0.15, p = 0.01). Persistent anemia was associated with lower scores on color-word inhibition/switching (β =  - 0.98; 95% CI - 1.78, - 0.18, p = 0.02). Errors of omission were significantly higher (worse) in those with persistent anemia (β = 2.67, 95% CI 0.18, 5.17, p = 0.04). Very low Hgb levels were significantly associated with lower color-word inhibition/switching scores (β =  - 1.33, 95% CI - 2.16, - 0.51; p = 0.002). Anemia and low GFR were associated with lower category fluency scores compared to non-anemic subjects with higher GFR (β =  - 1.09, 95% CI - 2.09, - 0.10, p = 0.03).

CONCLUSIONS

The presence of anemia, in addition to its severity and duration in children with CKD, is associated with poorer scores on select measures of EF. A higher resolution version of the Graphical abstract is available as Supplementary information.

P300, a tool for cognitive assessment in women with iron deficiency anemia: A systematic review

Iron-deficiency anemia (IDA) is a common nutritional disorder and an important risk factor for the development of mild cognitive impairment that may progress to dementia, if untreated. The anemic status due to iron deficiency (ID) alters the electrogenesis in the central nervous system. P300 is a cognitive evoked potential (CEP) used as an objective tool to assess cognitive function. Mild cognitive impairment is indicated by prolonged P300 wave latency and reduced amplitude. IDA is highly prevalent among women particularly in the reproductive phase and data on cognitive assessment using P300 in them are sparse. This review aims to analyze the evidence from recent literature regarding the effect of IDA on evoked potentials like P300 in women. A systematic literature review was conducted and databases, like PubMed, Medline, Scopus, and Google Scholar, were searched for studies from the last 20 years. We selected research papers that compared P300 between anemic women and controls of the same age, and evaluated the effects of iron supplementation on P300 in anemic women. Based on the inclusion criteria, three studies were found. The studies demonstrated impaired P300 potentials in anemic women that improved following iron supplementation. Promoting screening of anemic women with P300 aids in the early detection of subclinical cognitive decline. Ensuring adequate iron treatment can prevent mild cognitive impairment from progressing to severe forms like dementia and other neuropsychological disorders. Further studies utilizing P300 as a cognitive tool need to be encouraged to establish definite conclusions regarding its efficacy in detecting cognitive dysfunctions in anemia.

Hypoxia-Inducible Factor-Proline Hydroxylase Inhibitor in the Treatment of Renal Anemia

Background

Anemia is a common complication in CKD patients. Despite the use of iron and erythropoietin-stimulating agents, the control rate of anemia in CKD is not satisfying. Novel drugs are needed for anemia correction.

Summary

HIF-PHI, hypoxia-inducible factor-proline hydroxylase inhibitor, a novel class of therapeutic agents, has been developed to treat anemia in CKD patients. Its main effects comprised boosting EPO production, enhancing iron utilization, and suppressing hepcidin production. Several stage 2 and stage 3 clinical trials have been run to test its efficacy and safety in both nondialysis and dialysis patients, of which the results are very encouraging. Here, we summarize the mechanism, clinical applications, and clinical trials of HIF-PHI in treating renal anemia in order to give an overview of the new drug in clinical practices.

Key Messages

HIF-PHI is a novel therapeutic agent of treating renal anemia in CKD patients. It is quite effective in improving anemia, which is unaffected by inflammation. Besides, it may ameliorate lipid metabolism as well. Furthermore, the oral form may improve patients' compliances with treatment. Thus, it may be a good alternative of anemia correction in CKD patients.

Association between chronic kidney disease and Alzheimer's disease: an update

It has been accepted that kidney function is connected with brain activity. In clinical studies, chronic kidney disease (CKD) patients have been found to be prone to suffering cognitive decline and Alzheimer's disease (AD). The cognitive function of CKD patients may improve after kidney transplantation. All these indicators show a possible link between kidney function and dementia. However, little is known about the mechanism behind the relation of CKD and AD. This review discusses the associations between CKD and AD from the perspective of the pathophysiology of the kidney and complications and/or concomitants of CKD that may lead to cognitive decline in the progression of CKD and AD. Potential preventive and therapeutic strategies for AD are also presented. Further studies are warranted in order to confirm whether the setting of CKD is a possible new determinant for cognitive impairment in AD.

Mechanisms of cognitive dysfunction in CKD

Cognitive impairment is an increasingly recognized major cause of chronic disability and is commonly found in patients with chronic kidney disease (CKD). Knowledge of the relationship between kidney dysfunction and impaired cognition may improve our understanding of other forms of cognitive dysfunction. Patients with CKD are at an increased risk (compared with the general population) of both dementia and its prodrome, mild cognitive impairment (MCI), which are characterized by deficits in executive functions, memory and attention. Brain imaging in patients with CKD has revealed damage to white matter in the prefrontal cortex and, in animal models, in the subcortical monoaminergic and cholinergic systems, accompanied by widespread macrovascular and microvascular damage. Unfortunately, current interventions that target cardiovascular risk factors (such as anti-hypertensive drugs, anti-platelet agents and statins) seem to have little or no effect on CKD-associated MCI, suggesting that the accumulation of uraemic neurotoxins may be more important than disturbed haemodynamic factors or lipid metabolism in MCI pathogenesis. Experimental models show that the brain monoaminergic system is susceptible to uraemic neurotoxins and that this system is responsible for the altered sleep pattern commonly observed in patients with CKD. Neural progenitor cells and the glymphatic system, which are important in Alzheimer disease pathogenesis, may also be involved in CKD-associated MCI. More detailed study of CKD-associated MCI is needed to fully understand its clinical relevance, underlying pathophysiology, possible means of early diagnosis and prevention, and whether there may be novel approaches and potential therapies with wider application to this and other forms of cognitive decline.

Renal function and delirium in older fracture patients: different information from different formulas?

OBJECTIVES

the association between renal function and delirium has not been investigated in older fracture patients. Creatinine is frequently low in these subjects, which may influence the association between delirium and renal function as estimated with creatinine-based formulas. Cystatin C could be a more reliable filtration marker in these patients.

AIM

to confirm the association between renal function and delirium in older fracture patients comparing creatinine- and cystatin-based estimated glomerular filtration rate (eGFR) METHODS: patients aged 65+ requiring surgery for traumatic bone fractures were included. Six equations were used to calculate eGFR, based on serum creatinine and/or cystatin C obtained within 24 h of admission: Modification of Diet in Renal Disease (MDRD), Chronic Kidney Disease Epidemiology (CKD-EPIcr, CKD-EPIcys, CKD-EPIcr-cys) and Berlin Initiative Study equations (BIS-1, BIS-2). Delirium was identified with a chart-based method.

RESULTS

571 patients (mean age 83) were enrolled. Delirium occurred in the 34% and was associated with a lower eGFR regardless of the equation used. In a multivariable model, the association between moderate renal impairment (eGFR 30-60 ml/min/1.73 m2) and delirium remained significant in patients aged 75-84 and only when estimated with cystatin-based or BIS-1 equations. Only dementia was significantly associated with delirium in subjects 85+.

CONCLUSIONS

in older fracture patients, moderate renal impairment was independently associated with delirium only among subjects aged 75-84, when eGFR was estimated with cystatin-based or BIS 1 equations, and not with the most commonly used equations (MDRD, CKD-EPIcr).

Neurological and Psychological Changes in Hemodialysis Patients Before and After the Treatment

Neurological, psychological, and cognitive disorders in chronic kidney disease may contribute to poor quality of life in these patients. The aim of this study was to assess the electroencephalographic, psychological, and cognitive changes before and after hemodialysis (HD) compared with healthy controls (HC). Sixteen HD patients and 15 HC were enrolled. Electroencephalogram (EEG), Minnesota multiphasic personality inventory (MMPI-2) Satisfaction profile (SAT-P), and Neuropsychological test Global z-scores (NPZ5) were performed before (T0) and after (T1) HD treatment and in HC. Renal function, inflammatory markers and mineral metabolism indexes were also evaluated. Patients did not show significant differences before and after HD in the absolute and relative power of band of EEG, except in Theta/Alpha index (P < 0.001). At T1, HD patients showed significant differences in Beta, Delta and Theta band, in addition to Theta/alpha index, with respect to HC. Moreover, HD patients showed significant differences in specific MMPI-2 clinical and content scales, SAT-P domains and NPZ5 tests of memory and concentration with respect to HC. We also observed significant correlations between renal function, mineral metabolism, inflammatory markers and psychocognitive alterations. In our sample EEG abnormalities tend to reduce, but not significantly, after HD treatment and differences remain present with respect to HC. In HD patients cognitive and psychological alterations were associated with reduced quality of life and correlated with mineral metabolism and inflammation. Modification in EEG and in psychological and cognitive parameters should be assessed in a larger HD population to confirm our observation.

Therapeutic impact of rHuEPO on abnormal platelet APP, BACE 1, presenilin 1, ADAM 10 and Aβ expressions in chronic kidney disease patients with cognitive dysfunction like Alzheimer's disease: A pilot study

BACKGROUND

Cognitive dysfunction is reported to be a major cause of morbidity in chronic kidney disease (CKD). The senile plaques (SPs) in the brain are one of the most pathophysiological characteristics of cognitive dysfunction and its major constituent amyloid β (Aβ) released from amyloid precursor protein (APP) by β (BACE1) and γ (presenilin 1) secretases . Platelets contain more than 95% of the circulating APP and implicate as a candidate biomarker for cognitive decline. Recombinant human erythropoietin (rHuEPO) is a standard therapy for anemia in CKD and also acts as a neuroprotective agent. The aim of the study is to determine the impact of rHuEPO therapy on platelet APP processing in CKD with Cognitive Dysfunction.

METHODS

A total of 60 subjects comprising of 30 CKD without cognitive dysfunction and 30 CKD with cognitive dysfunction based on neuropsychological assessment. APP, BACE1, Presenilin 1, ADAM 10 (α secretase) and Aβ expressions in platelets were determined by western blotting and lipid peroxidation (LPO) in platelet rich plasma (PRP) was done by spectrophotometrically. The parameters were statistically compared with Alzheimer's disease (AD), Normocytic normochromic anemic and healthy subjects.

RESULTS

Significantly (p < 0.05) decreased APP, ADAM 10 while increased BACE1, Presenilin 1, Aβ and LPO were observed in CKD with cognitive dysfunction like AD subjects compared to other groups. The parameters were reassessed in CKD with cognitive dysfunction subjects after rHuEPO (100 IU/ kg, weekly twice, 6 months) therapy. All the parameters were retrieved significantly (p < 0.05) along with improved neuropsychological tests scoring after rHuEPO therapy.

CONCLUSIONS

This study demonstrated that rHuEPO is an effective neuroprotective agent in the context of CKD associated cognitive dysfunction and proved its clinical usefulness.

Human recombinant erythropoietin reduces sensorimotor dysfunction and cognitive impairment in rat models of chronic kidney disease

INTRODUCTION

Chronic kidney disease (CKD) can cause anaemia and neurological disorders. Recombinant human erythropoietin (rHuEPO) is used to manage anaemia in CKD. However, there is little evidence on the effects of rHuEPO on behaviour and cognitive function in CKD. This study aimed to evaluate the impact of rHuEPO in sensorimotor and cognitive functions in a CKD model.

METHODS

Male Wistar rats were randomly assigned to 4 groups: control and CKD, with and without rHuEPO treatment (1050 IU per kg body weight, once weekly for 4 weeks). The Morris water maze, open field, and adhesive removal tests were performed simultaneously to kidney damage induction and treatment. Markers of anaemia and renal function were measured at the end of the study.

RESULTS

Treatment with rHuEPO reduced kidney damage and corrected anaemia in rats with CKD. We observed reduced sensorimotor dysfunction in animals with CKD and treated with rHuEPO. These rats also completed the water maze test in a shorter time than the control groups.

CONCLUSIONS

rHuEPO reduces kidney damage, corrects anemia, and reduces sensorimotor and cognitive dysfunction in animals with CKD.

Peripapillary retinal nerve fiber layer thickness in patients with iron deficiency anemia

Purpose:

To evaluate the effect of iron deficiency anemia (IDA) on peripapillary retinal nerve fiber layer (RNFL) thickness with optical coherence tomography (OCT).

Materials and Methods:

102 female patients who had IDA (hemoglobin <12 g/dl, serum transferrin saturation <15%, serum iron <50 μg/dl, and serum ferritin <15 μg/dl) were enrolled in the study. Optic disc and RNFL parameters obtained by Cirrus high-definition OCT 4000 were compared with those of 49 age and sex-matched nonanemic individuals. The time between blood analysis and OCT measurements was 3.14 ± 5.6 (range, 0–28) days in the anemia group, and 3.5 ± 6.7 (range, 0–27) days in the control group (P = 0.76).

Results:

Average ages of 102 patients and 49 control subjects were 35.76 ± 10.112 (range, 18–66) years, and 36.08 ± 8.416 (range, 19–57) years (P = 0.850), respectively. The average RNFL thickness was 94.67 ± 9.380 in the anemia group, and 100.22 ± 9.12 in the control group (P = 0.001). Temporal, nasal, and lower quadrant average RNFL thicknesses of IDA group were thinner than the control group (P = 0.001, P = 0.013, P = 0.008). Upper quadrant RNFL thicknesses in IDA and control groups were similar. Correlation analysis revealed positive correlation between mean RNFL thickness and hemoglobin (r = 0.273), iron (r = 0.177), ferritin (r = 0.163), and transferrin saturations (r = 0.185), while a negative correlation was found between total iron binding capacity (r = −0.199) and mean RNFL thickness.

Conclusions:

Peripapillary RNFL thickness measured by OCT is thinner in adult female patients with IDA. It may have a significant influence on the management of many disorders such as glaucoma and neuro-ophthalmological diseases.

Cognitive impairment of patients with chronic renal disease on hemodialysis and its relationship with sociodemographic and clinical characteristics

Cognitive impairment and dementia commonly occur in individuals with chronic kidney disease, especially in advanced stages, but are still poorly diagnosed.

OBJECTIVE

To evaluate the cognitive ability of patients with chronic kidney disease on hemodialysis and its relationship with sociodemographic and clinical characteristics.

METHODS

A cross-sectional study was carried out in a Renal Replacement Therapy Unit in the interior of the State of São Paulo involving 99 patients. The data were collected through an individual interview, using the Sociodemographic and Clinical Characterization questionnaires and the Addenbrooke's Cognitive Examination - Revised (ACE-R) questionnaire.

RESULTS

Participants were predominantly male, with a mean age of 54.68 years. The mean ACE-R score was 64.26 points, and 76.76% of patients had lower-than-expected scores, suggesting the presence of cognitive impairment. A moderate, negative correlation was found between total score on the ACE-R and age (r= -0.38, p≤0.001), a moderate positive correlation with years of education (r=0.52, p≤0.001), and a weak positive correlation of total score with hemodialysis time (r=0.26, p≤0.001).

CONCLUSION

A relationship was found between cognitive ability and age, years of education and hemodialysis time, suggesting that individuals who were older, had less education and longer hemodialysis time presented greater cognitive impairment.

Neurological, psychological, and cognitive disorders in patients with chronic kidney disease on conservative and replacement therapy

Chronic kidney disease (CKD) is a highly prevalent condition in the world. Neurological, psychological, and cognitive disorders, related to CKD, could contribute to the morbidity, mortality, and poor quality of life of these patients. The aim of this study was to assess the neurological, psychological, and cognitive imbalance in patients with CKD on conservative and replacement therapy.Seventy-four clinically stable patients affected by CKD on conservative therapy, replacement therapy (hemodialysis (HD), peritoneal dialysis (PD)), or with kidney transplantation (KT) and 25 healthy controls (HC), matched for age and sex were enrolled. Clinical, laboratory, and instrumental examinations, as renal function, inflammation and mineral metabolism indexes, electroencephalogram (EEG), psychological (MMPI-2, Sat P), and cognitive tests (neuropsychological tests, NPZ5) were carried out.The results showed a significant differences in the absolute and relative power of delta band and relative power of theta band of EEG (P = 0.008, P < 0.001, P = 0.051), a positive correlation between relative power of delta band and C-reactive protein (CRP) (P < 0.001) and a negative correlation between estimated glomerular filtration rate (eGFR) (P < 0.001) and 1,25-dihydroxyvitamin D3 (1,25-(OH)2D3) (P < 0.001), in all the samples. Qualitative analysis of EEG showed alterations of Grade 2 (according to Parsons-Smith classification) in patients on conservative therapy, and Grade 2-3 in KT patients. The scales of MMPI-2 hysteria and paranoia, are significantly correlated with creatinine, eGFR, serum nitrogen, CRP, 1,25-(OH)2D3, intact parathyroid hormone (iPTH), phosphorus, and cynical and hysterical personality, are correlated with higher relative power of delta (P = 0.016) and theta band (P = 0.016). Moreover, all NPZ5 scores showed a significant difference between the means of nephropathic patients and the means of the HC, and a positive correlation with eGFR, serum nitrogen, CRP, iPTH, and vitamin D.In CKD patients, simple and noninvasive instruments, as EEG, and cognitive-psychological tests, should be performed and careful and constant monitoring of renal risk factors, probably involved in neuropsychological complications (inflammation, disorders of mineral metabolism, electrolyte disorders, etc.), should be carried out. Early identification and adequate therapy of neuropsychological, and cognitive disorders, might enable a better quality of life and a major compliance with a probable reduction in the healthcare costs.

Cross-sectional survey in CKD patients across Europe describing the association between quality of life and anaemia

BACKGROUND

Deteriorating renal function in chronic kidney disease (CKD) patients is commonly associated with reduced haemoglobin levels, adding to the already considerable humanistic burden of CKD. This analysis evaluated the impact of anaemia on disease burden in patients with CKD stages 3-4, and in those on dialysis.

METHODS

This was a descriptive, cross-sectional analysis of European data from an Adelphi CKD Disease-Specific Programme. This programme collected data from patients and their treating nephrologists/endocrinologists; patient- and physician-reported data were matched for each patient. Health-related quality of life (HRQoL) data were obtained through patient completion of the EQ-5D, SF-12 and KDQOL-36. Additional information was obtained via physician reporting of patient symptoms, and patients' reports of impaired activity. Anaemia was defined by haemoglobin level and/or current use of erythropoiesis stimulating agents.

RESULTS

Significant, but modest Spearman's rank correlations were observed between haemoglobin levels and extent of HRQoL impairment, regardless of instrument used (range 0.19-0.23; all P-values < 0.0001). When stratified by anaemia status, impairment was consistently lower for anaemic than non-anaemic CKD patients across measurement scales (e.g. EQ-5D index value [standard deviation {SD}] 0.72 [0.31] vs 0.83 [0.23], respectively; P < 0.0001). Physician-reported patient tiredness was associated with increased disease burden at all levels of CKD studied (total EQ-5D index value [SD] in patients reporting no tiredness vs tiredness 0.81 [0.26] vs 0.70 [0.30] respectively; P < 0.0001) with P < 0.0001 for no tiredness vs tiredness at all stages of CKD. The presence of anaemia was associated with impaired activity levels at CKD stages 3 (37.5 % vs 28.4 %, respectively; P = 0.0044) and 4 (48.1 % vs 39.9 %, respectively; P = 0.0292), and in patients on dialysis (52.0 % vs 45.0 %, respectively; P = 0.0732).

CONCLUSIONS

The analysis found that CKD patients with anaemia typically had a lower HRQoL than those without anaemia. The impairment correlated with anaemia was more apparent in non-dialysis patients with CKD stages 3 or 4 than in those receiving dialysis. Coexisting CKD and anaemia may have an impact on patient HRQoL similar to other chronic conditions such as diabetes, epilepsy or certain forms of cancer.

Neurological complications in chronic kidney disease patients

Chronic kidney disease (CKD) is associated with a high prevalence of cerebrovascular disorders such as stroke, white matter diseases, intracerebral microbleeds and cognitive impairment. This situation has been observed not only in end-stage renal disease patients but also in patients with mild or moderate CKD. The occurrence of cerebrovascular disorders may be linked to the presence of traditional and non-traditional cardiovascular risk factors in CKD. Here, we review current knowledge on the epidemiological aspects of CKD-associated neurological and cognitive disorders and discuss putative causes and potential treatment. CKD is associated with traditional (hypertension, hypercholesterolaemia, diabetes etc.) and non-traditional cardiovascular risk factors such as elevated levels of oxidative stress, chronic inflammation, endothelial dysfunction, vascular calcification, anaemia and uraemic toxins. Clinical and animal studies indicate that these factors may modify the incidence and/or outcomes of stroke and are associated with white matter diseases and cognitive impairment. However, direct evidence in CKD patients is still lacking. A better understanding of the factors responsible for the elevated prevalence of cerebrovascular diseases in CKD patients may facilitate the development of novel treatments. Very few clinical trials have actually been performed in CKD patients, and the impact of certain treatments is subject to debate. Treatments that lower LDL cholesterol or blood pressure may reduce the incidence of cerebrovascular diseases in CKD patients, whereas treatment with erythropoiesis-stimulating agents may be associated with an increased risk of stroke but a decreased risk of cognitive disorders. The impact of therapeutic approaches that reduce levels of uraemic toxins has yet to be evaluated.

Peripapillary retinal nerve fibre layer thickness in women with iron deficiency anaemia

OBJECTIVE

To evaluate peripapillary retinal nerve fibre layer (RNFL) thickness in adult women with iron deficiency anaemia and healthy control subjects.

METHODS

Women with iron deficiency anaemia and age- and sex-matched healthy control subjects were sequentially recruited and underwent detailed ophthalmic examination, including spectral-domain optical coherence tomography (OCT). Serum haemoglobin (Hb), iron and ferritin concentrations, total iron-binding capacity (TIBC) and mean corpuscular volume were determined.

RESULTS

Peripapillary RNFL thicknesses in the nasal and inferior quadrants were significantly smaller in patients (n = 40) than in controls (n = 40). In the patient group, there were significant correlations between inferior quadrant RNFL thickness and Hb, and between nasal quadrant RNFL thickness and serum iron and ferritin concentrations, and TIBC.

CONCLUSION

Iron deficiency anaemia reduces RNFL thickness in adult women.

Retinal fiber layer thickness in children with thalessemia major and iron deficiency anemia

PURPOSE

We aimed to measure peripapillary retinal nerve fiber layer (RNFL) thickness in children with thalassemia major (tha-major), children with iron deficiency anemia (IDA), and children in a healthy control group.

MATERIALS AND METHODS

A total of 47 children with tha-major and 22 children with IDA were selected from two pediatric hematology outpatient clinics as our experimental groups, while 35 healthy children were randomly selected from a primary school to act as a control group. After a complete eye examination was conducted and intraocular pressure measurements were obtained, RNFL measurements were performed using optical coherence tomography, and the information was recorded for statistical analysis.

RESULTS

The mean age of the participants was 9.65 ± 4.13 years in the tha-major group, 9.14 ± 2.53 years in the IDA group, and 9.13 ± 3.29 years in the control group, respectively, with no statistically significant difference among the three groups (p > 0.05). Mean peripapillary RNFL thickness was 119.38 ± 35.49 microns in the tha-major group, 184.00 ± 31.14 microns in the IDA group, and 187.73 ± 27.36 microns in the control group. It was significantly thinner in all quadrants in the tha-major group vs. the other two groups (p < 0.01), and in only the inferior quadrant in the IDA group (p < 0.05). Average RNLF thickness correlated positively with mean hemoglobin value (r = 0.488; p < 0.001) and negatively with mean ferritin level (r = -0.544; p < 0.001), but no correlations with mean number of transfusions and mean visual acuity were observed (p > 0.05).

CONCLUSION

The study revealed that peripapillary RNFL is thinner in tha-major in all quadrants and in only the inferior quadrant in IDA. Thinning of the RNLF correlated with hemoglobin value and ferritin level, but not with number of transfusions and visual acuity.

Peripapillary Retinal Nerve Fiber Layer Thickness in Children with Iron Deficiency Anemia

Purpose.

To evaluate peripapillary retinal nerve fiber layer (RNFL) thickness in children with iron deficiency anemia (IDA) in comparison with healthy controls and to investigate the correlation between peripapillary RNFL thicknesses and the hematologic parameters in these subjects.

Methods.

Forty eyes of 40 children with a diagnosis of IDA (anemic group) and 40 eyes of 40 age- and sex-matched healthy children (control group) were enrolled in this study. Peripapillary RNFL thickness measurements were performed using Cirrus HD optical coherence tomography (OCT).

Results.

Mean age of each group was 11.3±2.7 years. Average RNFL and RNFLs of superior and inferior quadrants were significantly thinner in the anemic group than in the control group (p=0.006, p=0.005, and p=0.005, respectively). In addition, average peripapillary RNFL thickness and RNFL thicknesses of superior, inferior, and temporal quadrants were correlated with hemoglobin levels (r1=0.734, p1<0.001, r2=0.456, p2=0.005, r3=0.598, p3<0.001, r4=0.349, p4=0.037, respectively) in anemic group.

Conclusions.

We found that children with IDA had different peripapillary RNFL profile measured by Cirrus HD spectral-domain OCT. We caution ophthalmologists when they measure RNFL thickness in children to diagnose glaucoma or other neuro-ophthalmic disorders.

Kidney transplantation improves cognitive and psychomotor functions in adult hemodialysis patients

BACKGROUND

Kidney failure is believed to have a negative impact on cognitive function, and cognitive impairment is common among maintenance hemodialysis (HD) patients. Previous studies have shown a beneficial effect of kidney transplantation in certain cognitive tests but not across all cognitive domains assessed. But, most of these studies performed a cross-sectional analysis, suffered from lack of standardization of adequate dialysis dose, hemoglobin level, and insufficient sensitivity of neuropsychological tests. The aim of this study was to evaluate the effect of successful kidney transplantation on cognitive and psychomotor function in adequately dialyzed HD patients without severe anemia, using sensitive neuropsychological tests.

METHODS

Twenty-one medically stable patients (aged 45.1 ± 7.9 years) on maintenance HD (7.6 ± 4.2 years) were investigated before and 20.5 ± 8.5 months after successful kidney transplantation using Complex Reactiometer Drenovac, a battery of computer-generated psychological tests which measure a simple visual discrimination of signal location, short-term memory, simple convergent visual orientation and convergent thinking.

RESULTS

Our findings indicated significantly better cognitive and psychomotor performance after transplantation on tests that assess processing speed, attention, short time memory, convergent thinking and executive functioning. Also, significant negative correlation between follow-up time after transplantation and cognitive and psychomotor performance in minimum time of solving test of convergent thinking was found.

CONCLUSION

We conclude that cognitive and psychomotor functions are superior after successful kidney transplantation compared with HD, and that early beneficial effects of transplantation are not transient and cognitive and psychomotor performance might be even improved in time following successful transplantation.

[Cognitive impairment and chronic kidney disease: which links?]

Ageing of the population leads to an increase of cognitive disorders and chronic renal failure incidence. Compared to the general population, prevalence of cognitive impairment is more important in renal failure patients, especially in dialyzed patients. No direct link has been established between renal failure and cognitive impairment. The care of older and older patients and the high frequency of vascular risk factors, in particular hypertension and diabetes, partially explain the prevalence of vascular dementia and Alzheimer disease in this population. Other factors as the anemia, phosphocalcic metabolism disorders facilitate the cognitive impairment. The present work reviews the links existing between chronic renal failure and cognitive impairment.

Effect of iron deficiency anemia on visual evoked potential of growing children

Iron deficiency anemia is one of the most prevalent yet neglected nutritional deficiencies in the world. Iron is an essential micronutrient and it is ubiquitous in distribution in body. Iron deficiency leads to anemia, hampered physical growth and capacity, and decreased immunoprotective mechanisms. Impairments in cognitive and motor development in children are also seen in iron deficiency. There is increasing number of evidence to support that iron plays important role in central nervous system functions that include synthesis of neurotransmitters and myelination of the nerve. The objective of our study was to observe the effect of iron deficiency anemia on visual evoked potential (VEP) in children between 6 and 24 months of age. The subjects were categorized on the basis of hematological parameters in two groups: iron replete children in the control group (n=25) and iron deplete children in the anemic group (n=25). Iron status of the children was also assessed. Due care was taken to exclude all conditions known to adversely affect the visual evoked potential or the iron status of the children. Flash VEP was studied in all children from each eye individually. In both eyes each of the three waves (N1, P1 and N2) of the flash VEP showed longer latencies (p<0.05) in the anemic group compared with the control group. A negative correlation was found between the severity of iron deficiency anemia and latencies of waves of VEP. Hence, there is a need for prevention and early detection of iron deficiency anemia in growing infants.

[Contribution of central venous oxygen saturation in postoperative blood transfusion decision]

OBJECTIVE

The aim of this study was to assess the value of central venous oxygen saturation (ScvO(2)) for the decision of blood transfusion in comparison with the criteria of the French guidelines for blood transfusion (2003).

STUDY DESIGN

Prospective, observational.

PATIENTS AND METHODS

Sixty patients, haemodynamically stable, for whom a blood transfusion (BT) was discussed in the postoperative course of general surgery, were included. ScvO(2) (%) and haemoglobin (g/dl) were measured before and after BT. Patients were retrospectively divided into two groups according to ScvO(2) measured before BT (< or >or=70%). Results are expressed as median.

RESULTS

The ScvO(2) before transfusion was greater or equal to 70% in 25 (47.2%) patients. Following BT, the ScvO(2) increased significantly (from 57.8 to 68.5%) in the group with initial ScvO(2) less than 70% whereas it was unchanged in patients with initial ScvO(2) greater or equal 70% (from 76.8 to 76.5%). Twenty patients (37.7%) did not meet the French guidelines for BT criteria. Eighteen patients out of 33 that met the criteria had ScvO(2) greater or equal 70% before BT while 13 patients with ScvO(2) less than 70% were not detected by these same criteria.

CONCLUSION

ScvO(2) could be a relevant biological parameter to complete the current guidelines for BT in stable patient with a central venous catheter during the postoperative period.