Improvement of brain function in hemodialysis patients treated with erythropoietin

Evaluation of Event-Related Potentials in Somatic Diseases - Systematic Review

Many somatic illnesses (e.g. hypertension, diabetes, pulmonary and cardiac diseases, hepatitis C, kidney and heart failure, HIV infection, Sjogren's disease) may impact central nervous system functions resulting in emotional, sensory, cognitive or even personality impairments. Event-related potential (ERP) methodology allows for monitoring neurocognitive processes and thus can provide a valuable window into these cognitive processes that are influenced, or brought about, by somatic disorders. The current review aims to present published studies on the relationships between somatic illness and brain function as assessed with ERP methodology, with the goal to discuss where this field of study is right now and suggest future directions.

Comparative Safety of Long-Acting vs. Short-Acting Erythropoiesis-Stimulating Agents Among Patients Undergoing Hemodialysis

Both short-acting (epoetin alfa or beta) and long-acting (darbepoetin alfa or PEG-epoetin) erythropoiesis-stimulating agents (ESAs) are commonly prescribed for patients with kidney failure undergoing maintenance hemodialysis. We compared the risks of major adverse cardiovascular events (MACE) and of all-cause mortality associated with receipt of short- vs. long-acting ESAs. This retrospective cohort analysis included Medicare hemodialysis beneficiaries aged ≥ 18 years in the United States Renal Data System from January 2015 to December 2017. We included adults who survived > 90 days after initiating hemodialysis and received either short- or long-acting ESAs. Outcomes were MACE (first occurrence of stroke, acute myocardial infarction, or cardiovascular-related mortality) and all-cause mortality. After stabilized inverse probability of treatment weighting, Cox proportional hazards regression models were used to estimate the hazard ratio (HR) and 95% confidence interval (CI) for each outcome. Of 68,607 patients (mean age: 65 years, 45% females), 33,658 (49%) received long-acting ESAs and 34,949 (51%) received short-acting ESAs. There was no difference in the risk of MACE associated with receipt of short- vs. long-acting ESAs (HR: 1.02 (95% CI: 0.98-1.08)). However, long-acting (vs. short-acting) ESA receipt was associated with a lower risk of all-cause mortality (HR: 0.91 (95% CI: 0.87-0.96)). Compared with short-acting ESAs, long-acting ESAs were associated with a lower risk of all-cause mortality, with no difference in the risk of MACE. Future studies with a longer follow-up are needed to confirm these findings.

Role of erythropoietin in the treatment of Alzheimer's disease: the story so far

This review aims to explore the potential of erythropoietin, a glycopeptide hormone, as a treatment option for Alzheimer's disease, which is the commonest cause of dementia. Despite years of focus and research, therapeutic options for Alzheimer's disease are not yet completely satisfactory. And as people age, they are likely to develop Alzheimer's Disease, further pressuring the healthcare system. So, it is definite to develop treatment options that meet superior outcomes with minimal negative effects. A comprehensive review of the literature was conducted in PubMed and Google Scholar using a combination of keywords, including Alzheimer's disease, dementia, erythropoietin, and neuroprotection. Search results were assessed for relevance before using the data for this study. The beneficial implications of erythropoietin as a therapeutic option have been explored, along with the side effects and mechanisms of erythropoietin in Alzheimer's disease. Overall, the authors' review indicates that erythropoietin presents a promising avenue for mitigating the progression of Alzheimer's disease, with minimal associated side effects.

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.

More rapid progression of brain atrophy in patients on peritoneal dialysis compared with hemodialysis: The VCOHP Study

We previously reported that brain atrophy was more severe and progressed more rapidly in patients with end-stage kidney disease on peritoneal dialysis (PD) than those with non-dialysis-dependent chronic kidney disease. However, it remains unknown whether there is a difference between patients on PD and hemodialysis (HD). In total, 73 PD and 34 HD patients who underwent brain magnetic resonance imaging (MRI) were recruited for a cross-sectional analysis. Among them, 42 PD and 25 HD patients who underwent a second brain MRI after 2 years were recruited for a longitudinal analysis. T1-weighted MRI images were analyzed. Total gray matter volume (GMV), total white matter volume, and cerebrospinal fluid volume were segmented, and each volume was quantified using statistical parametric mapping software. The ratio of GMV (GMR) was calculated by dividing GMV by intracranial volume, to adjust for variations in head size. We compared GMR between PD and HD patients in the cross-sectional analysis and the annual change in GMR (AC-GMR) in the longitudinal analysis. In the cross-sectional analysis, age- and sex-adjusted GMR was significantly lower in PD than HD patients [least square mean (LSM): 39.2% vs. 40.0%, P = 0.018]. AC-GMR was significantly greater in PD than HD patients and this difference remained significant even after adjustment for potential confounding factors (LSM: -0.68 vs. -0.28 percentage-points/year, P = 0.011). In conclusion, the present study demonstrated a more rapid progression of brain atrophy in PD patients compared with HD patients. We demonstrated that decline in GMR progressed significantly more rapidly in PD than HD patients independent of potential confounding factors. GMR gray matter volume ratio, HD hemodialysis, PD peritoneal dialysis.

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.

Lower haemoglobin concentrations are associated with impaired cognition in patients with carotid artery occlusion

Background

Patients with carotid artery occlusion (CAO) are vulnerable to cognitive impairment (CI). Anaemia is associated with CI in the general population. We hypothesized that lower haemoglobin is associated with cognitive impairment (CI) in patients with CAO and that this association is accentuated by cerebral blood flow (CBF).

Methods

104 patients (mean age 66±8 years, 77% men) with complete CAO from the Heart-Brain Connection study were included. Anaemia was defined as haemoglobin < 12 g/dL for women and < 13 g/dL for men. Cognitive test results were standardized into z-scores (using a reference group) in four cognitive domains. Patients were classified as cognitively impaired when ≥ one domain was impaired. The association between lower haemoglobin and both cognitive domain z-scores and the presence of CI was assessed with adjusted (age, sex, education and ischaemic stroke) regression models. Total CBF (measured with phase contrast MRI) and the interaction term haemoglobin*CBF were additionally added to the analyses.

Results

Anaemia was present in 6 (6%) patients and was associated with CI (RR 2.54, 95% CI 1.36; 4.76). Lower haemoglobin was associated with the presence of CI (RR per minus 1 g/dL haemoglobin 1.15, 95% CI 1.02; 1.30). This association was strongest for the attention-psychomotor speed domain (RR for impaired attention-psychomotor speed functioning per minus 1 g/dL haemoglobin 1.27, 95% CI 1.09;1.47) and ß for attention-psychomotor speed z-scores per minus 1 g/dL haemoglobin -0.19, 95% CI -0.33; -0.05). Adjustment for CBF did not affect these results and we found no interaction between haemoglobin and CBF in relation to cognition.

Conclusion

Lower haemoglobin concentrations are associated with CI in patients with complete CAO, particularly in the domain attention-psychomotor speed. CBF did not accentuate this association. If validated in longitudinal studies, haemoglobin might be a viable target to prevent cognitive deterioration in patients with CAO.

Evaluation of switching treatment from high dose of darbepoetin to lower dose of roxadustat in Japanese hemodialysis patients

Roxadustat is one of the oral hypoxia-inducible factor prolyl hydroxylase inhibitors (HIF-PHIs) that stimulates erythropoiesis and regulates the genes related to iron metabolism. The treatment of HIF-PHIs is useful compared with that of erythropoietin stimulating agent (ESA) using various instruments and procedures. Few clinical researchers have examined the efficacy and safety of switching treatment from Darbepoetin to Roxadustat in Japanese hemodialysis (HD) patients. However, HIF-PHIs have severe adverse drug reactions, such as thrombotic events. In the present study, we evaluated the lower dose of roxadustat in HD patients receiving high dose of ESA therapy. Eighteen anemic HD patients receiving an ESA, that is,, darbepoetin over 40 μg per week, were enrolled in this study. The treatment of these patients was changed to 20 mg of roxadustat three times weekly for 6 months, after which doses were adjusted to achieve a hemoglobin (Hb) target of 10.0-12.0 g/dL. An increase of 58.1 ± 32.5 mg roxadustat three times weekly increased Hb. It also achieved and then maintained levels within the target range at month 6. Ferritin levels of more than 100 ng/mL or TSAT levels of more than 20% were maintained during the 6-month treatment periods with oral or intravenous iron supplementation. It seems unnecessary to increase the initial dose of roxadustat for patients using high doses of ESA. It is suggested that a reconsideration of the starting dose of roxadustat in Japanese HD patients is needed. (Ikegami General Hospital, Medical Corporation SHOWAKAI、Approval number: 2020-4).

Association between Cerebral Oxygenation, as Evaluated with Near-Infrared Spectroscopy, and Cognitive Function in Patients Undergoing Hemodialysis

INTRODUCTION

The prevalence of cognitive impairment in patients undergoing hemodialysis (HD) is higher than that in healthy controls. To date, studies on the association between cognitive function and cerebral oxygenation in these patients are limited. Therefore, in this study, we aimed to cross-sectionally investigate the association between cognitive assessment scores and clinical factors, including cerebral oxygenation, in patients undergoing HD.

METHODS

In this observational study, 193 HD patients were included. Cerebral regional oxygen saturation (rSO2) was monitored using an INVOS 5,100c oxygen saturation monitor. Poor cognition was defined as a Mini-Mental State Examination (MMSE) score ≤23. We analyzed the association between MMSE score and clinical factors, including cerebral rSO2.

RESULTS

MMSE score in HD patients included in this study was 26.8 ± 3.3. There were 164 patients (85%) with MMSE score ≥24 and 29 patients (15%) with an MMSE score ≤23. In the patients with MMSE score ≥24, cerebral rSO2 (53.8% ± 8.3%) was significantly higher than that in patients with MMSE score ≤23 (49.5% ± 9.8%; p = 0.013). Multivariable linear regression analysis was performed using the following confounding factors: age, mean blood pressure, cerebral rSO2, HD duration, ultrafiltration rate, hemoglobin, serum Cr, serum calcium, serum phosphate, total cholesterol, high-density lipoprotein cholesterol levels, serum albumin, presence of diabetes mellitus or chronic glomerulonephritis, history of comorbid cardiovascular or cerebrovascular disease, and use of renin-angiotensin-aldosterone system inhibitors or vitamin D analogs. MMSE score was independently and significantly associated with age (standardized coefficient: -0.244) and cerebral rSO2 (standardized coefficient: 0.180).

CONCLUSIONS

MMSE score was independently associated with age (negative effect) and cerebral rSO2 (positive effect) in this cross-sectional study. Further prospective studies are needed to clarify whether maintaining cerebral oxygenation prevents the deterioration of cognitive function in patients undergoing HD.

Associations of cerebral oxygenation with hemoglobin levels evaluated by near-infrared spectroscopy in hemodialysis patients

Hemoglobin (Hb) is associated with cerebral oxygenation status owing to its important role of carrying oxygen to systemic tissues. However, data concerning the associations between Hb levels and cerebral regional oxygen saturation (rSO₂) of hemodialysis (HD) patients is limited. We aimed to identify these associations to consider a target Hb level for renal anemia management. This study included 375 HD patients. Cerebral rSO₂ before HD was monitored using the INVOS 5100c oxygen saturation monitor. Multivariable linear regression analysis showed that cerebral rSO₂ was independently associated with natural logarithm (Ln)-HD duration (standardized coefficient: -0.36), mean blood pressure (standardized coefficient: 0.13), pH (standardized coefficient: -0.10), serum albumin (standardized coefficient: 0.14), presence of diabetes mellitus (standardized coefficient: -0.20), and Hb level (standardized coefficient: 0.29). Furthermore, a generalized linear model with restricted cubic spline function was used to investigate the non-linear association between cerebral rSO₂ and Hb levels. In the multivariable analysis for the adjustment with Ln-HD duration, mean blood pressure, pH, serum albumin, and presence of diabetes mellitus, a linear relationship was demonstrated between the two variables (p for linearity = 0.79). Hb levels revealed the positive and significant association with cerebral rSO₂ in this study. Moreover, the relationship between cerebral rSO₂ and Hb level was proven to be linear. Therefore, the target Hb level in renal anemia management would be considered to be the upper limits for the appropriate management of renal anemia by previous guidelines and position statement from the viewpoint of maintaining cerebral oxygenation in HD patients.

Erythropoietin as a Neuroprotective Molecule: An Overview of Its Therapeutic Potential in Neurodegenerative Diseases

Erythropoietin (EPO) is a cytokine mainly induced in hypoxia conditions. Its major production site is the kidney. EPO primarily acts on the erythroid progenitor cells in the bone marrow. More and more studies are highlighting its secondary functions, with a crucial focus on its role in the central nervous system. Here, EPO may interact with up to four distinct isoforms of its receptor (erythropoietin receptor [EPOR]), activating different signaling cascades with roles in neuroprotection and neurogenesis. Indeed, the EPO/EPOR axis has been widely studied in the neurodegenerative diseases field. Its potential therapeutic effects have been evaluated in multiple disorders, such as Alzheimer’s disease, Parkinson’s disease, amyotrophic lateral sclerosis, spinal cord injury, as well as brain ischemia, hypoxia, and hyperoxia. EPO is showing great promise by counteracting secondary neuroinflammatory processes, reactive oxygen species imbalance, and cell death in these diseases. Multiple studies have been performed both in vitro and in vivo, characterizing the mechanisms through which EPO exerts its neurotrophic action. In some cases, clinical trials involving EPO have been performed, highlighting its therapeutic potential. Together, all these works indicate the potential beneficial effects of EPO.

Erythropoietin prevents dementia in hemodialysis patients: a nationwide population-based study

Erythropoietic medications such as including erythropoietin (EPO) are known to be neuroprotective and to correlate with improved cognitive functions. However, it is not known whether supplementation with EPO reduces the risk of dementia in end-stage renal disease (ESRD) patients receiving hemodialysis (HD). Here, we determined whether EPO levels correlate with the incidence of different dementia subtypes, including Alzheimer’s disease (AD), vascular dementia (VaD), and unspecified dementia (UnD), and whether such associations vary with annual cumulatively defined daily doses (DDDs) of EPO for ESRD patients receiving HD. This retrospective study included data from 43,906 adult ESRD patients who received HD between 1999 and 2010. Using hazard ratios and Cox regression models, we found that patients receiving EPO had a 39% lower risk of general dementia than those in the non-EPO group. Similarly, the risks of VaD and UnD was lower for patients in the EPO cohort. The risk of dementia was further reduced in HD patients treated with EPO in combination with iron. Our results suggest that the use of EPO medications in HD patients is associated with a reduced risk of VaD and UnD, but not AD, regardless of whether EPO is used alone or in combination with iron.

Types of Erythropoietin-Stimulating Agents and Mortality among Patients Undergoing Hemodialysis

BACKGROUND

Despite the widespread use of erythropoietin-stimulating agents (ESAs) to treat anemia in patients undergoing hemodialysis, the relative mortality risks associated with use of different types of ESAs are unknown.

METHODS

To compare the mortality risk associated with use of short-acting ESAs versus long-acting ESAs, we conducted a nationwide cohort study of 194,698 hemodialysis patients in Japan who received either a short-acting (epoetin α/β or epoetin κ) or a long-acting (darbepoetin or epoetin β pegol) ESA. Study outcomes were 2-year all-cause and cause-specific mortality. In addition to Cox proportional hazards models, we performed an instrumental variable analysis in which facility-level long-acting ESA prescription rates were taken as the instrumental variable.

RESULTS

During the 2-year follow-up period, 31,557 deaths occurred. In a multivariable Cox model, long-acting ESA users had a 13% higher rate of deaths compared with short-acting ESA users, a significant difference (P<0.001). Similar results were obtained in other analyses. This difference in risk was pronounced among patients receiving high doses of ESA (for whom the adjusted 2-year number needed to harm for death was 30.8). Long-acting ESA use was associated with an increased rate of death from cardiovascular diseases, infection, and malignancies. In the instrumental variable analysis, long-acting ESA users remained at a significantly higher risk of death. Compared with anemic (hemoglobin 9.0-9.9 g/dl) short-acting ESA users, long-acting ESA users who achieved more optimal hemoglobin levels (10.0-10.9 g/dl) showed a higher mortality rate.

CONCLUSIONS

Among patients undergoing hemodialysis, use of long-acting ESAs might be associated with a higher risk of death than use of short-acting ESAs.

Effect of valerian on cognitive disorders and electroencephalography in hemodialysis patients: a randomized, cross over, double-blind clinical trial

BACKGROUND

The prevalence of cognitive disorders in hemodialysis patients is twice as high as the general population, while these disorders often are undiagnosed. Timely prevention and treatment can improve their personal and social functions. Aim of study was determined the effect of Valerian on cognitive disorders and electroencephalography (EGG) in hemodialysis patients.

METHODS

This crossover, double-blind clinical trial was conducted on 39 hemodialysis patients. The patients were randomly divided into two groups. Group A (n = 19) took Valerian capsules and Group B (n = 20) received placebo capsules 60 min before bedtime for one month. The type of treatment was replaced between the two groups after a one-month wash-out. The Mini Mental State Examination (MMSE) questionnaire was completed and EGG was performed before and after intervention in both periods.

RESULTS

The cognitive scores of the Group valerian were increased significantly in the first (p = 0.003) and the second (p = 0.005) periods. In addition, the mean increase in the cognitive scores in the Group valerian was significant in the first (p = 0.028) and the second periods (p = 0.030). However, the changes in EGG showed no significant difference before and after intervention in two groups.

CONCLUSION

The findings of this study indicated that valerian could be effective and significantly improve patients' cognitive status; however, no significant changes were observed in the electroencephalography of the hemodialysis patients.

TRIAL REGISTRATION

IRCT201606076318N7 -2016-06-17.

Arterial damage and cognitive decline in chronic kidney disease patients

In the general population aortic stiffening, assessed by carotid femoral pulse wave velocity (cf-PWV), is associated with cognitive dysfunction (CO/DY). Data in chronic kidney disease (CKD) are limited. This study tests the hypothesis that large artery stiffness and microvascular damage in CKD patients are related to the damage of brain microcirculation reflected by impaired cognitive function. A cross-sectional study enrolled 151 patients (mean age 58.4 years; 64.5% males; 44 patients with CKD stage 1; 47 with stage 2; 25 with stage 3; and 35 with stage 4). Cognitive impairment, assessed by the Mini Mental State Examination (MMSE), the Clock - drawing test (Clock-test), and the Instrumental Activity of Daily Living (IADL), was considered as primary outcome. We measured systolic and pulse pressures at the brachial and aortic sites and cf-PWV. Our patients revealed a significant linear deterioration in all the domains of cognitive function according to CKD stages. High values of cf-PWV (P = 0.029) and aortic pulse pressure (aPP) (P < 0.026) were independent determinants of cognitive decline assessed by the MMSE. The present trial supports the hypothesis of an interaction between the kidney, large artery damage, central pressure pulsatility, and the injury of brain microcirculation. In clinical practice, cf-PWV and aPP measurements may help to predict cognitive decline. Whether the reduction in aortic stiffness following an aggressive treatment translates into improved cognitive outcomes remains to be determined.

Does inflammation affect outcomes in dialysis patients?

Chronic, low-grade inflammation is a common comorbid condition in chronic kidney disease (CKD), and particularly in chronic dialysis patients. In this review, we consider the question of whether inflammation affects outcomes in dialysis patients. Levels of proinflammatory cytokines, as well as C-reactive protein, are elevated in chronic dialysis patients. Multiple factors likely contribute to chronic inflammatory activation in kidney disease patients including the uremic milieu, lifestyle and epigenetic influences, infectious and thrombotic events, the dialysis process, and dysbiosis. Increased inflammatory markers in both CKD and chronic dialysis patients are associated with adverse clinical outcomes including all-cause mortality, cardiovascular events, kidney disease progression, protein energy wasting and diminished motor function, cognitive impairment, as well as other adverse consequences including CKD-mineral and bone disorder, anemia, and insulin resistance. Strategies that have been shown to reduce chronic systemic inflammation in CKD and chronic dialysis patients include both pharmacological and nonpharmacological interventions. However, despite evidence that systemic inflammatory markers can be lowered in kidney disease patients treated with various strategies, evidence that this improves clinical outcomes is largely unavailable and represents an important future research direction. Overall, there is strong observational evidence that inflammation is high in chronic dialysis patients and that this is independently associated with numerous adverse clinical outcomes. Targeting inflammation represents a potentially novel and attractive strategy if it can indeed improve adverse outcomes common in this population.

Latency and amplitude changes in cognitive event related potentials due to hemodialysis

Chronic kidney disease impacts the cognitive abilities of patients, and yet few works have analyzed functional electroencephalographic changes on event-related potentials before and after an hemodialysis session. This work shows that, as a consequence of hemodialysis, cognitive potential waveforms suffer changes, occurring with reduced latency $( \sim 50$ ms) and with larger amplitude $( \sim 0.128\mathrm {a}$.u.) after the treatment session. While only a limited sample of five patients is reported herein, the observed changes immediately after hemodialysis could be a sign of central nervous system alterations that are not clinically evaluated. Signs like these could entail an early indicator of possible evolution into some neuropathology.

A Controlled Study of Sorbent Suspension Dialysis in Chronic Liver Disease and Hepatic Encephalopathy

To investigate the role of extracorporeal detoxification in cirrhotic patients with advanced hepatic encephalopathy not responding to medical treatment, 20 patients were randomized to receive six hours of additional sorbent dialysis or ongoing standardized medical treatment. Following treatment, the clinical stage of encephalopathy remained unchanged in both groups. Abnormal sensory evoked potentials improved following sorbent dialysis (N70 latency, 128 ms before versus 110 ms after treatment, P<0,05; cervico-cranial transmission, 7.7 ms versus 6.8 ms, P<0.01) indicating improvement in important aspects of cerebral function. In contrast, brain function remained unchanged following medical treatment (N70 latency, 114 ms versus 113 ms; cervico-cranial transmission, 7.7 ms versus 7.2 ms, P=NS, respectively). Serum benzodiazepine levels decreased significantly after sorbent dialysis but not after medical treatment. Biocompatibility of sorbent dialysis was limited and clinical complications occurred in a proportion of patients. In conclusion, a six-hour treatment with sorbent suspension dialysis did not ameliorate the clinical stage of HE but improved neurophysiologic function in cirrhotic patients who had not responded to conventional medical treatment.

End stage renal disease is associated with development of dementia

There is controversy regarding the extent of risk for dementia in patients with end stage renal disease (ESRD) who are undergoing hemodialysis (HD) or peritoneal dialysis (PD). We examined data from Taiwan's Longitudinal Health Insurance Database, and used Cox proportional hazard regression analysis to compare the development of dementia in 72,934 HD and PD patients with 72,934 matched controls from January 1, 1999 to December 31, 2010. The results indicate an increased risk for dementia overall in HD patients (adjusted hazard ratio [aHR] = 1.64, p < 0.0001) and PD patients (aHR = 2.21, p < 0.0001). HD and PD patients also had significantly greater aHRs for vascular dementia (VaD) and unspecified dementia (UnD), but only HD patients had a significantly greater aHR for Alzheimer's disease (AD). Further research is needed to confirm whether management of ESRD with PD can reduce the incidence of AD, and to identify the mechanisms by which ESRD increases the risk of dementia.

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.

Effect of renal transplantation on cognitive function in hemodialysis patients: a longitudinal study

BACKGROUND

The literature notes high prevalence of cognitive function (CF) impairment among hemodialysis patients. Renal transplantation by reversing metabolic factors should improve cognitive function; however, results in post-transplant patients are inconsistent. Lack of longitudinal studies, variable and small patient population, variable renal function and post-transplantation period and use of non-specific tests make results difficult to interpret. We looked at CF in stable hemodialysis patients just prior to live renal transplantation and approximately 3 months subsequently using well-validated electrophysiological study of P300 cognitive potential obtained by auditory oddball paradigm using multiple scalp electrodes.

METHODS

Ten healthy age- and gender-matched controls (group 1) and 20 end-stage kidney disease (ESKD) male patients on maintenance hemodialysis with no other comorbidities that affect CF were studied before (group 2) and 3 months after successful transplantation (group 3).

RESULTS

ESKD population had mean age of 29.7 ± 7.5 years, with mean dialysis vintage and post-transplant period being 10.3 ± 6.9 and 3.2 ± 0.4 months, respectively. Mean P300 latencies in groups 1, 2 and 3 were 319 ± 33.6, 348.6 ± 27.8 and 316.4 ± 33.4 ms, respectively (P < 0.001 group 1 vs 2 and group 2 vs 3; group 1 vs 3 NS). Mean P300 amplitude in groups 1, 2 and 3 was 27.9 ± 12.8, 13.4 ± 8.6 and 14.6 ± 9.4 µV, respectively (P < 0.001 group 1 vs 2 and group 1 vs 3; group 2 vs 3 NS). P300 latencies correlated negatively with hemoglobin and serum albumin.

CONCLUSIONS

ESKD patients have impaired CF as documented by prolonged P300 latencies. There was normalization of P300 latencies post-transplantation indicating role of uremic toxins in CF impairment.

Cognition in People With End-Stage Kidney Disease Treated With Hemodialysis: A Systematic Review and Meta-analysis

BACKGROUND

Cognitive impairment is associated with poorer quality of life, risk for hospitalization, and mortality. Cognitive impairment is common in people with end-stage kidney disease treated with hemodialysis, yet the severity and specific cognitive deficits are uncertain.

STUDY DESIGN

Systematic review and meta-analysis.

SETTING & POPULATION

Adults receiving hemodialysis compared with the general population, people with non-dialysis-dependent chronic kidney disease (NDD-CKD), people receiving peritoneal dialysis, or people with nondialyzed chronic kidney failure.

SELECTION CRITERIA FOR STUDIES

Randomized controlled trials, cohort or cross-sectional studies without language restriction.

INDEX TESTS

Validated neuropsychological tests of cognition.

OUTCOMES

Cognitive test scores, aggregated by cognitive domain: orientation and attention, perception, memory, language, construction and motor performance, concept formation and reasoning, and executive functions.

RESULTS

42 studies of 3,522 participants. Studies were of high or uncertain risk of bias, assessed by the Newcastle-Ottawa Scale. People treated with hemodialysis had worse cognition than the general population, particularly in attention (n=22; standardized mean difference [SMD], -0.93; 95% CI, -1.18 to -0.68). Hemodialysis patients performed better than nondialyzed patients with chronic kidney failure in attention (n=6; SMD, 0.70; 95% CI, 0.45 to 0.96) and memory (n=6; SMD, 0.36; 95% CI, 0.08 to 0.63), but had poorer memory than the general population (n=16; SMD, -0.41; 95% CI, -0.91 to 0.09) and people with NDD-CKD (n=5; SMD, -0.40; 95% CI, -0.60 to -0.21). There were insufficient data to show other differences among people receiving hemodialysis and those receiving peritoneal dialysis or with NDD-CKD.

LIMITATIONS

Potentially biased studies, not wholly adjusted for education. High heterogeneity, mainly due to the large variety of tests used to assess cognition.

CONCLUSIONS

People treated with hemodialysis have impaired cognitive function compared to the general population, particularly in the domains of orientation and attention and executive function. Cognitive deficits in specific domains should be further explored in this population and should be considered when approaching education and chronic disease management.

Comparison of dementia risk between end stage renal disease patients with hemodialysis and peritoneal dialysis--a population based study

A higher risk of dementia was reported in patients undergoing maintenance hemodialysis (HD) compared to those undergoing peritoneal dialysis (PD). Selection bias and competing risk of death were not considered in previous studies. The aim of this study was to investigate dementia risk in patients undergoing HD and PD by using the Taiwan Longitudinal Health Insurance Database. We enrolled 52,332 incident HD patients and 3292 incident PD patients who were older than 40 years between January 1, 1998 and December 31, 2007. During the study period, 3775 patients were diagnosed with dementia in the HD group (177.5 per 10,000 person-years incidence rate) and 181 patients in the PD group (145.9 per 10,000 person-years incidence rate). The results revealed that the higher hazard ratio of HD compared with PD for dementia disappeared after controlling for demographic characteristics, propensity score, and competing death risk (subdistribution hazard ratio was 1.086; 95% confidence interval, 0.940–1.255). In conclusion, HD did not increase the risk of dementia in dialysis-dependent patients compared to PD.

Cerebral microbleeds and cognitive decline in a hemodialysis patient: Case report and review of literature

Cerebral microbleeds (CMBs) are small hemosiderin deposits indicative of prior cerebral microscopic hemorrhage and previously thought to be clinically silent. Recent population-based cross-sectional studies and prospective longitudinal cohort studies have revealed association between CMB and cognitive dysfunction. In the general population, CMBs are associated with age, hypertension, and cerebral amyloid angiopathy. In the chronic kidney disease (CKD) population, diminished estimated glomerular filtration rate has been found to be an independent risk factor for CMB, raising the possibility that a uremic milieu may predispose to microbleeds. In the end-stage renal disease (ESRD) population on hemodialysis, the incidence of microbleeds is significantly higher compared with a control group without history of CKD or stroke. We present an ESRD patient on chronic hemodialysis with a history of gradual cognitive decline and progressive CMBs. Through this case and literature review, we illustrate the need to develop detection and prediction models to treat this frequent development in ESRD patients.

Risk factors for cognitive dysfunction in CKD and hypertensive subjects

PURPOSE

Cognitive dysfunction (CO/DY) in chronic kidney disease (CKD) patients has long been recognized. Hypertension is also associated with CO/DY. The study describes associated factors with CO/DY in CKD patients compared to hypertensive subjects.

METHODS

Ninety-six hypertensive subjects without CKD, 19 patients with CKD stages I-II, 33 with CKD III, 42 with CKD stage IV, 33 on hemodialysis (HD) and 33 on peritoneal dialysis (PD) were included in our study. Cognitive impairment measured by MMSE, clock-drawing test and IADL was considered as primary outcome.

RESULTS

In all groups tested, age was significantly associated with CO/DY by almost all cognitive function tests. Among CKD patients, CKD stage and DM were significantly associated with CO/DY by all three cognitive function tests. PTH levels were also associated with CO/DY by MMSE and clock-drawing tests. In hypertensives, pulse pressure (PP) was associated with CO/DY by clock-drawing and IADL tests, while those receiving CCBs as monotherapy were less likely to have CO/DY by IADL test. For dialysis patients, DM was significantly related to CO/DY by MMSE and clock-drawing tests. In the same group of patients Hb <11 g/dl was significantly correlated with CO/DY by MMSE, dialysis modality and Kt/V >1.2 by IADL test. PD patients were less likely to present with CO/DY by clock-drawing test.

CONCLUSIONS

In every CKD stage, the risk of CO/DY increased significantly. Low Hb levels (Hb <11 g/dl) and increased serum PTH levels were associated with CO/DY while DM plays also a significant role in cognitive function deterioration. Among hypertensive subjects, those with PP ≤60 mmHg or receiving CCBs showed a better executive function.

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.

Continuous cognitive improvement 1 year following successful kidney transplant

Successful kidney transplantation was recently shown to lead to improvement in the cognitive performance of patients on chronic dialysis. To examine whether the early cognitive benefits of transplantation continue to develop over time, along with the patients' ongoing recovery, we addressed these questions in a prospective controlled study of 27 dialyzed patients who subsequently received a kidney transplant, 18 dialyzed patients awaiting kidney transplant, and 30 matched controls without kidney disease. Overall, successful kidney transplant contributed to a statistically significant improvement in performance on tests of motor/psychomotor speed, visual planning, memory, and abstract reasoning tested 1 year later. We also studied whether the cognitive performance of patients maintained on dialysis is stable or declines over time and found that it actually declined over this time even in adequately dialyzed patients. Measures of memory functions were particularly affected. This study indicates that the early beneficial effects of transplantation are not transient and were still evident 1 year following transplantation.

Hemoglobin concentration and cognitive impairment in the renal REasons for Geographic And Racial Differences in Stroke (REGARDS) Study

BACKGROUND

There is growing interest in determining the degree of anemia, which is clinically significant. The goal of this study was to determine the association between hemoglobin concentration and cognitive impairment in a large sample of U.S. adults.

METHODS

We used cross-sectional data from 19,701 adults participating in the REasons for Geographic And Racial Differences in Stroke study. Cognitive impairment was defined as a score of 4 or less on the six-item screener. Hemoglobin was analyzed in 1 g/dL increments relative to the World Health Organization (WHO) threshold (<13 g/dL for men and <12 g/dL for women).

RESULTS

The mean hemoglobin concentration was 13.7 ± 1.5 g/dL. The prevalence of cognitive impairment increased from 4.3% among individuals with a hemoglobin >3 g/dL above the WHO threshold to 16.8% for those with a hemoglobin ≥2 g/dL below the WHO threshold. After adjustment for demographics, chronic health conditions, health status, and inflammation, the association between reduced hemoglobin and cognitive impairment was attenuated and no longer significant, including among those with hemoglobin ≥2 g/dL below the WHO threshold (odds ratio 1.39, 95% confidence interval = 0.94-2.04). A test for linear trend was of borderline significance (p value = .06). For 94% of the sample within 2 g/dL of the WHO threshold, there was no relationship between hemoglobin concentration and the odds of cognitive impairment. The associations did not differ by sex and race.

CONCLUSIONS

Within a large sample of community-dwelling adults, there was no significant association between hemoglobin concentration and cognitive impairment after multivariable adjustment.

Vascular risk factors and cognitive impairment in chronic kidney disease: the Chronic Renal Insufficiency Cohort (CRIC) study

BACKGROUND AND OBJECTIVES

Cognitive impairment is common among persons with chronic kidney disease, but the extent to which nontraditional vascular risk factors mediate this association is unclear.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

We conducted cross-sectional analyses of baseline data collected from adults with chronic kidney disease participating in the Chronic Renal Insufficiency Cohort study. Cognitive impairment was defined as a Modified Mini-Mental State Exam score>1 SD below the mean score.

RESULTS

Among 3591 participants, the mean age was 58.2±11.0 years, and the mean estimated GFR (eGFR) was 43.4±13.5 ml/min per 1.73 m2. Cognitive impairment was present in 13%. After adjustment for demographic characteristics, prevalent vascular disease (stroke, coronary artery disease, and peripheral arterial disease) and traditional vascular risk factors (diabetes, hypertension, smoking, and elevated cholesterol), an eGFR<30 ml/min per 1.73 m2 was associated with a 47% increased odds of cognitive impairment (odds ratio 1.47, 95% confidence interval 1.05, 2.05) relative to those with an eGFR 45 to 59 ml/min per 1.73 m2. This association was attenuated and no longer significant after adjustment for hemoglobin concentration. While other nontraditional vascular risk factors including C-reactive protein, homocysteine, serum albumin, and albuminuria were correlated with cognitive impairment in unadjusted analyses, they were not significantly associated with cognitive impairment after adjustment for eGFR and other confounders.

CONCLUSIONS

The prevalence of cognitive impairment was higher among those with lower eGFR, independent of traditional vascular risk factors. This association may be explained in part by anemia.

Dementia and cognitive impairment in ESRD: diagnostic and therapeutic strategies

Cognitive impairment, including dementia, is a common but poorly recognized problem among patients with end-stage renal disease (ESRD), affecting 16-38% of patients. Dementia is associated with high risks of death, dialysis withdrawal, hospitalization, and disability among patients with ESRD; thus, recognizing and effectively managing cognitive impairment may improve clinical care. Dementia screening strategies should take into account patient factors, the time available, the timing of assessments relative to dialysis treatments, and the implications of a positive screen for subsequent management (for example, transplantation). Additional diagnostic testing in patients with cognitive impairment, including neuroimaging, is largely based on the clinical evaluation. There is limited data on the efficacy and safety of pharmacotherapy for dementia in the setting of ESRD; therefore, decisions about the use of these medications should be individualized. Management of behavioral symptoms, evaluation of patient safety, and advance care planning are important components of dementia management. Prevention strategies targeting vascular risk factor modification, and physical and cognitive activity have shown promise in the general population and may be reasonably extrapolated to the ESRD population. Modification of ESRD-associated factors such as anemia and dialysis dose or frequency require further study before they can be recommended for treatment or prevention of cognitive impairment.

Cognitive performance before and after kidney transplantation: a prospective controlled study of adequately dialyzed patients with end-stage renal disease

Patients with end-stage renal disease (ESRD) who receive dialysis have been shown to have impaired neuropsychological performance. It remains unclear, however, whether cognitive deficits associated with ESRD and/or dialysis are reversible after successful kidney transplantation. Thus, the main purpose of this study was to longitudinally compare the cognitive performance of adequately dialyzed patients with ESRD before and shortly after kidney transplantation. Twenty-two dialyzed patients with ESRD who subsequently received a kidney transplant, 20 dialyzed patients who were medically qualified and awaiting kidney transplant but did not receive it, and 30 matched controls were the participants for this study. Overall, our results demonstrate that a successful kidney transplant is associated with improved neuropsychological performance in patients with ESRD. Specifically, a significant improvement was seen on measures of psychomotor speed, visual planning, retrieval of learnt material, and abstract thinking. Additionally, the degree of cognitive improvement following kidney transplant was significantly associated with some pre-, intra-, and postoperative factors (e.g., age, duration of chronic kidney disease, postoperative graft function). The results of this study also show that the cognitive performance of adequately dialyzed patients without a kidney transplant, although often below that of matched controls, remains relatively stable over time.

Anemia and 9-year domain-specific cognitive decline in community-dwelling older women: The Women's Health and Aging Study II

OBJECTIVES

To test the hypothesis that anemia (hemoglobin <12 g/dL) is associated with a faster rate of cognitive decline over 9 years in a community-dwelling sample of women aged 70 to 80 at baseline.

DESIGN

A population-based, prospective cohort study.

SETTING

East Baltimore, Maryland.

PARTICIPANTS

Four hundred thirty-six women sampled to be representative of the two-thirds least-disabled women aged 70 to 80 at baseline (1994-1996).

MEASUREMENTS

Nine-year trajectories of cognitive decline, analyzed using linear random effects models, in the domains of immediate verbal recall, delayed verbal recall, psychomotor speed, and executive function.

RESULTS

At baseline and after adjustment for demographic and disease covariates, women with anemia were slower to complete a test of executive function; the difference in baseline function between women with anemia and those without was -0.43 standard deviations (SDs) (95% confidence interval (CI)=-0.74 to -0.13) on the Trail Making Test Part B. During follow-up, anemia was associated with a faster rate of decline in memory. Between baseline and Year 3, the difference in the rates of decline between women with anemia and those without was -0.18 SDs per year (95% CI=-0.29 to -0.06) on the Hopkins Verbal Learning Test (HVLT) and -0.15 SDs per year (95% CI=-0.26 to -0.04) on the HVLT-Delayed.

CONCLUSION

Anemia was associated with poorer baseline performance on a test of executive function and with faster rates of decline on tests of immediate and delayed verbal recall. If this relationship is causal, it is possible that treatment of anemia could prevent or postpone cognitive decline.

Effect of Hemodialysis on Cognitive Function in ESRD Patients

BACKGROUND

Uremia is associated with impairment of different cognitive functions. However the pathogenesis of this cognitive dysfunction is unknown.

OBJECTIVE

In this study, long-latency event related potentials (ERPs) were used to assess changes in cortical function due to hemodialysis treatment.

METHODS

In this cross-sectional study, we measured event related potentials in 15 end stage renal disease (ESRD) patients maintained on hemodialysis, two hours before and two hours after they underwent hemodialysis and compared their data with a strictly age and sex matched healthy control group. The P3 was elicited by using standard auditory "odd-ball" paradigm and the data obtained was statistically analyzed (Wilcoxon signed ranks, Mann Whitney).

RESULTS

Before hemodialysis, the patients' P3 latency (347.73 +/- 39.47 ms) was significantly increased as compared with that of healthy control group (308.4 +/- 13.73 ms) (p = 0.001). After hemodialysis, P3 latency of the patients showed a significant decrease (347.73 +/- 39.47 ms to 325.20 +/- 37.15 ms, p = 0.001). P3 latency after dialysis was not significantly different from controls. No significant correlation was noted between various biochemical parameters (hemoglobin, blood urea, creatinine, uric acid and calcium) and P3 latency or amplitude.

CONCLUSIONS

Removal of uremic toxins by hemodialysis leads to an improvement in cognitive processing.

Interpretation and review of health-related quality of life data in CKD patients receiving treatment for anemia

Recent evidence suggests that targeting higher hemoglobin values with erythropoiesis stimulating agents (ESAs) may lack mortality benefits and may even result in adverse cardiovascular complications when used in chronic kidney disease patients. However, ESAs are frequently reported to result in improvements in health-related quality of life (HRQOL). The purpose of this review is to evaluate the magnitude and nature of ESA-associated improvements in HRQOL, as well as to understand how to interpret the clinical significance of HRQOL data. HRQOL findings should be analyzed not by statistical significance but rather by using a minimal clinically important difference approach, or, alternatively, a distribution-based approach (such as Cohen's effect size). HRQOL domains that are most improved with ESAs relate to physical symptoms, vitality, energy, and performance; domains of social functioning and mental health show modest improvement, whereas the domains of emotional functioning and pain show very little improvement. Additional domains not measured by commonly used instruments (such as the SF-36) that have been shown to improve with ESAs include sleep, cognitive functioning, and sexual functioning. The maximal increase in HRQOL per incremental increase in hemoglobin appears to occur in the range of 10-12 g/dl. Beyond this range, additional normalization of hemoglobin (to 12-14 g/dl) results in continued (albeit blunted) improvements in HRQOL.

Effect of epoetin alpha therapy on cognitive function in anaemic patients with solid tumours undergoing chemotherapy

The primary aim of this study was to assess whether epoetin alpha (Ea) would improve cognitive performance in a group of anaemic cancer patients receiving chemotherapy. The secondary aim was to confirm the positive impact of Ea on haematological parameters, and quality of life (QOL). Fifty patients with solid tumours and haemoglobin (Hb) <11.0 g/dL received Ea 40,000 units once weekly for 12 weeks and were administered the Mini-Mental State Examination and the European Organization for Research and Treatment of Cancer (QLQ-C30) questionnaire prior to Ea therapy and at study completion. No clinically significant alterations were observed on cognitive function during Ea treatment. Changes in cognitive function were unrelated to Hb change and there were no significant differences in cognitive performance between Ea responders and non-responders. The analyses revealed clinically significant improvements in Hb levels, physical and role function, and clinically meaningful reductions in fatigue. Hb changes were significantly associated with the magnitude of improvement in QOL parameters. The lack of a clinical benefit in cognition observed in this study during Ea treatment may redirect the focus of research from enhancing to maintaining cognitive function, since stability in cognitive performance through time may be as well clinically important.

Erythropoiesis-stimulating agents and other methods to enhance oxygen transport

Oxygen is essential for life, and the body has developed an exquisite method to collect oxygen in the lungs and transport it to the tissues. Hb contained within red blood cells (RBCs), is the key oxygen-carrying component in blood, and levels of RBCs are tightly controlled according to demand for oxygen. The availability of oxygen plays a critical role in athletic performance, and agents that enhance oxygen delivery to tissues increase aerobic power. Early methods to increase oxygen delivery included training at altitude, and later, transfusion of packed RBCs. A breakthrough in understanding how RBC formation is controlled included the discovery of erythropoietin (Epo) and cloning of the EPO gene. Cloning of the EPO gene was followed by commercial development of recombinant human Epo (rHuEpo). Legitimate use of this and other agents that affect oxygen delivery is important in the treatment of anaemia (low Hb levels) in patients with chronic kidney disease or in cancer patients with chemotherapy-induced anaemia. However, competitive sports was affected by illicit use of rHuEpo to enhance performance. Testing methods for these agents resulted in a cat-and-mouse game, with testing labs attempting to detect the use of a drug or blood product to improve athletic performance (doping) and certain athletes developing methods to use the agents without being detected. This article examines the current methods to enhance aerobic performance and the methods to detect illicit use.

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.