Cognitive Changes in Peritoneal Dialysis Patients: A Multicenter Prospective Cohort Study

Research on cognitive impairment and potential risk factors in peritoneal dialysis patients: An observational study

The objective of this study is to investigate the associated risk factors and their effects on cognitive impairment (CI) in patients undergoing peritoneal dialysis. A retrospective analysis was conducted on the basic information of 268 patients who underwent continuous ambulatory peritoneal dialysis (CAPD) at our hospital from January 2020 to September 2023. Cognitive function was assessed using the Montreal Cognitive Assessment Scale during their subsequent dialysis visits. Participants were categorized into a CI group and a cognitively normal group. Blood and other biological samples were collected for relevant biomarker analysis. Subsequently, we analyzed and compared the factors influencing CI between the 2 groups. The prevalence of CI among CAPD patients was 58.2%. Compared to the cognitively normal group, the CI group had a higher prevalence of alcohol consumption, lower levels of education, and reduced serum uric acid levels (P < .05). There was also a higher incidence of autoimmune diseases such as systemic lupus erythematosus in the CI group (P < .05). In terms of dialysis efficacy, the residual kidney Kt/V and residual kidney Ccr were significantly lower in the CI group compared to the cognitively normal group. In blood parameters, the CI group showed elevated total cholesterol levels and lower serum calcium concentrations (P < .05). Logistic regression analysis identified male gender, older age, lower educational attainment, hypercholesterolemia, and elevated high-sensitivity C-reactive protein levels as independent risk factors for CI in CAPD patients (P < .05). Additionally, in this patient cohort, dialysis duration and residual renal function were protective factors against CI (P < .05). CI is prevalent among PD patients. Elevated high-sensitivity C-reactive protein levels, male gender, older age, lower educational attainment, and hypercholesterolemia constitute an independent risk factor for CI in CAPD patients, whereas residual renal function acts as a protective element.

Serum albumin and white matter hyperintensities

People living with HIV and those diagnosed with alcohol use disorders (AUD) relative to healthy individuals commonly have low levels of serum albumin, substantiated as an independent predictor of cardiovascular events. White matter hyperintensities (WMH)-a neuroimaging feature of cerebral small vessel disease-are also related to cardiovascular disease. Despite consensus regarding associations between high levels of urine albumin and WMH prevalence, and low serum albumin levels and impaired cognitive functioning, relations between serum albumin and WMH burdens have rarely been evaluated. Here, a sample including 160 individuals with AUD, 142 living with HIV, and 102 healthy controls was used to test the hypothesis that serum albumin would be inversely related to WMH volumes and directly related to cognitive performance in the two diagnostic groups. Although serum albumin and periventricular WMH volumes showed an inverse relationship in both AUD and HIV groups, this relationship persisted only in the HIV group after consideration of traditional cardiovascular (i.e., age, sex, body mass index (BMI), nicotine use, hypertension, diabetes), study-relevant (i.e., race, socioeconomic status, hepatitis C virus status), and disease-specific (i.e., CD4 nadir, HIV viral load, HIV duration) factors. Further, serum albumin contributed more significantly than periventricular WMH volume to variance in performance on a verbal learning and memory composite score in the HIV group only. Relations in both HIV and AUD groups between albumin and hematological red blood cell markers (e.g., hemoglobin, hematocrit) suggest that in this sample, serum albumin reflects hematological abnormalities. Albumin, a simple serum biomarker available in most clinical settings, may therefore help identify periventricular WMH burden and performance levels in specific cognitive domains in people living with HIV. Whether serum albumin contributes mechanistically to periventricular WMH in HIV will require additional investigation.

Peritoneal Dialysis-Related Infections

Peritoneal dialysis (PD) represents an important treatment choice for patients with kidney failure. It allows them to dialyze outside the hospital setting, facilitating enhanced opportunities to participate in life-related activities, flexibility in schedules, time and cost savings from reduced travel to dialysis centers, and improved quality of life. Despite its numerous advantages, PD utilization has been static or diminishing in parts of the world. PD-related infection, such as peritonitis, exit-site infection, or tunnel infection, is a major concern for patients, caregivers, and health professionals-which may result in hesitation to consider this as treatment or to cease therapy when these complications take place. In this review, the definition, epidemiology, risk factors, prevention, and treatment of PD-related infection on the basis of the contemporary evidence will be described.

[Neuropsychological impairments in patients undergoing peritoneal dialysis treatment]

BACKGROUND

Patients with chronic kidney disease on hemodialysis (HD) often have cognitive deficits. However, there are few studies that have examined the neuropsychological impairments of patients receiving peritoneal dialysis (PD).

METHODS

Executive functions, processing speed and verbal memory were assessed in 27 PD patients, 42 HD patients, and 42 healthy participants (HP). Systolic blood pressure and total time on renal replacement therapy (RRT) were controlled statistically. Associations between performance and clinical factors were analyzed using correlations and multiple regression.

RESULTS

The DP group showed better performance compared to the HD group in verbal fluency, working memory, cognitive flexibility, planning and decision making. The DP group showed worse execution than the HP group in verbal inhibition and memory. Executive function scores were positively associated with total months on PD, total months on RRT, total months on HD, albumin, total cholesterol, and phosphorus, and negatively with ferritin.

CONCLUSION

Global executive functioning was more optimal in PD patients than in HD patients. The results show the positive effect of PD on executive functions, which must be taken into account when choosing the TRS. The associations observed between biochemical factors and performance show the importance of maintaining an adequate nutritional status in these patients.

Risk factors for cognitive impairment in patients with chronic kidney disease

BACKGROUND

Chronic kidney disease (CKD) patients have been found to be at risk of concurrent cognitive dysfunction in previous studies, which has now become an important public health issue of widespread concern.

AIM

To investigate the risk factors for concurrent cognitive dysfunction in patients with CKD.

METHODS

This is a prospective cohort study conducted among patients with CKD between October 2021 and March 2023. A questionnaire was formulated by literature review and expert consultation and included questions about age, sex, education level, per capita monthly household income, marital status, living condition, payment method, and hypertension.

RESULTS

Logistic regression analysis showed that patients aged 60-79 years [odds ratio (OR) = 1.561, P = 0.015] and ≥ 80 years (OR = 1.760, P = 0.013), participants with middle to high school education (OR = 0.820, P = 0.027), divorced or widowed individuals (OR = 1.37, P = 0.032), self-funded patients (OR = 2.368, P = 0.008), and patients with hypertension (OR = 2.011, P = 0.041) had a higher risk of cognitive impairment. The risk of cognitive impairment was lower for those with a college degree (OR = 0.435, P = 0.034) and married individuals.

CONCLUSION

The risk factors affecting cognitive dysfunction are age, 60-79 years and ≥ 80 years; education, primary school education or less; marital status, divorced or widowed; payment method, self-funded; hypertension; and CKD.

Comparison of the effects of peritoneal dialysis and hemodialysis on spontaneous brain activity in CKD patients: an rs-fMRI study

OBJECTIVE

To compare the effects of peritoneal dialysis and hemodialysis on spontaneous brain activity in patients with end-stage renal disease.

METHODS

A total of 52 dialysis patients with end-stage renal disease, including 25 patients with chronic kidney disease undergoing hemodialysis (HD-CKD) and 27 patients with chronic kidney disease undergoing peritoneal dialysis (PD-CKD), and 49 healthy controls (normal control) were included. All participants underwent neuropsychological testing (Mini-Mental State Examination and Montreal cognitive assessment) and resting-state functional magnetic resonance imaging. Fractional amplitude of low frequency fluctuations and Regional Homogeneity algorithms were employed to evaluate spontaneous brain activity. Statistical analysis was performed to discern differences between the groups.

RESULTS

When compared with the normal control group, the PD-CKD group exhibited significant alterations in fractional amplitude of low frequency fluctuations in various cerebellum regions and other brain areas, while the HD-CKD group showed decreased fractional amplitude of low frequency fluctuations in the bilateral pericalcarine cortex. The Regional Homogeneity values in the PD-CKD group were notably different than those in the normal control group, particularly in regions such as the bilateral caudate nucleus and the right putamen.

CONCLUSION

Both peritoneal dialysis and hemodialysis modalities impact brain activity, but manifest differently in end-stage renal disease patients. Understanding these differences is crucial for optimizing patient care.

Serum albumin and white matter hyperintensities

Urine albumin, high in kidney disease, predicts cardiovascular incidents and CNS white matter hyperintensity (WMH) burdens. Serum albumin - a more general biomarker which can be low in several disorders - including kidney and liver disease, malnutrition, and inflammation - also predicts cardiovascular events and is associated with cognitive impairment in several clinical populations; relations between serum albumin and WMH prevalence, however, have rarely been evaluated. In a sample of 160 individuals with alcohol use disorder (AUD), 142 infected with HIV, and 102 healthy controls, the hypothesis was tested that lower serum albumin levels would predict larger WMH volumes and worse cognitive performance irrespective of diagnosis. After considering traditional cardiovascular risk factors (e.g., age, sex, body mass index (BMI), nicotine use, hypertension, diabetes) and study-relevant variables (i.e., primary diagnoses, race, socioeconomic status, hepatitis C virus status), serum albumin survived false discovery rate (FDR)-correction in contributing variance to larger periventricular but not deep WMH volumes. This relationship was salient in the AUD and HIV groups, but not the control group. In secondary analyses, serum albumin and periventricular WMH along with age, sex, diagnoses, BMI, and hypertension were considered for hierarchical contribution to variance in performance in 4 cognitive domains. Albumin survived FDR-correction for significantly contributing to visual and verbal learning and memory performance after accounting for diagnosis. Relations between albumin and markers of liver integrity [e.g., aspartate transaminase (AST)] and blood status (e.g., hemoglobin, red blood cell count, red cell distribution width) suggest that in this sample, albumin reflects both liver dysfunction and hematological abnormalities. The current results suggest that albumin, a simple serum biomarker available in most clinical settings, can predict variance in periventricular WMH volumes and performance in visual and verbal learning and memory cognitive domains. Whether serum albumin contributes mechanistically to periventricular WMH prevalence will require additional investigation.

Subjective cognitive complaints in end-stage renal disease: a systematic review and meta-analysis

Cognitive impairment is common in patients with end-stage renal disease (ESRD) and is associated with compromised quality of life and functional capacity, as well as worse clinical outcomes. Most previous research and reviews in this area were focused on objective cognitive impairment, whereas patients' subjective cognitive complaints (SCCs) have been less well-understood. This systematic review aimed to provide a broad overview of what is known about SCCs in adult ESRD patients. Electronic databases were searched from inception to January 2022, which identified 221 relevant studies. SCCs appear to be highly prevalent in dialysis patients and less so in those who received kidney transplantation. A random-effects meta-analysis also shows that haemodialysis patients reported significantly more SCCs than peritoneal dialysis patients (standardised mean difference -0.20, 95% confidence interval -0.38 to -0.03). Synthesis of longitudinal studies suggests that SCCs remain stable on maintenance dialysis treatment but may reduce upon receipt of kidney transplant. Furthermore, SCCs in ESRD patients have been consistently associated with hospitalisation, depression, anxiety, fatigue, and poorer quality of life. There is limited data supporting a strong relation between objective and subjective cognition but preliminary evidence suggests that this association may be domain-specific. Methodological limitations and future research directions are discussed.

Effects of cognitive impairment and assisted peritoneal dialysis on exit-site infection in older patients

BACKGROUND

Elderly peritoneal dialysis (PD) patients required assistance for a variety of PD-related tasks. The usefulness of assisted PD in reducing the peritonitis risk has been reported; however, there is little evidence on the effectiveness of assisted PD in preventing exit-site infections in older patients.

METHODS

This was a single-center, prospective cohort study. Thirty-three patients (mean age: 74.8 ± 5.9 years) on PD were evaluated for cognitive impairment (CI) using the Japanese version of the Montreal Cognitive Assessment. They were also evaluated to determine whether they performed the exit-site care procedure alone or with assistance. Patients were categorized into four groups based on the presence or absence of CI and the presence or absence of exit-site care assistance. They were followed up until the occurrence of peritonitis and exit-site infection at the end of the follow-up.

RESULTS

Altogether, 8, 8, and 17 patients were assigned to the "without CI and without assistance", "without CI and with assistance", and "with CI and with assistance groups", respectively; no patients were assigned to the "with CI and without assistance group". Six and 16 patients experienced peritonitis and exit-site infection during follow-up, respectively. Kaplan-Meier analysis and log-rank tests revealed that the "without CI and without assistance group" was significantly associated with exit-site infection (log-rank < 0.05).

CONCLUSION

Patients who did not receive assistance for exit-site care were at a higher risk of exit-site infections, even in the absence of CI. Caregiver assistance is important for preventing exit-site infections in older patients on PD.

Cognitive Dysfunction and Its Risk Factors in Patients Undergoing Maintenance Hemodialysis

OBJECTIVE

Cognitive impairment (CI) in Maintenance hemodialysis (MHD) is attracting increasing attention. This study aims to clarify the prevalence and risk factors for cognitive dysfunction in patients on MHD who have no history of stroke.

METHODS

A total of 99 patients with no history of stroke undergoing MHD were enrolled. Global cognitive function was evaluated using the Montreal Cognitive Assessment scale. Attention and executive functions were evaluated by the Digital Span (DS) test and the Color Trail Test (CTT). The Hamilton Depression and Anxiety scales were used to assess depression and anxiety status. The effects of patient background factors, laboratory indicators, anxiety, and depression on cognitive dysfunction were examined by regression analysis.

RESULTS

There were 69.70% of the patients had general CI, 65.65% had depression, and 57.57% had anxiety. The forward and backward DS in the cognitively impaired (CI) group were shorter than in the normal cognitive function (NCF) group (P<0.05). Times required for CTT-I, CTT-II, and CTT II - CTT I were longer in the CI group than in the NCF group (P<0.05). Hemoglobin levels were lower, and parathyroid hormone (PTH) and uric acid levels were higher in the CI group than in the NCF group (P<0.05). Hemoglobin levels were negatively correlated with CI in these patients (odds ratio [OR] 0.634, P<0.05) and PTH, and uric acid levels were positively correlated with CI (OR 1.028, P<0.05; and OR 1.011, P<0.05). The proportions of patients with diabetes and depression were higher in the CI group (P<0.05).

CONCLUSION

There was a high prevalence of CI with significant impairment of attention and executive ability in MHD patients who had no stroke history. Hemoglobin may protect cognitive function, while diabetes, PTH, and uric acid levels may be risk factors. Depressive and anxiety states may aggravate CI in MHD patients.

Factors that contribute to the cognitive impairment in elderly dialysis patients

AIM

To evaluate the cognitive function in dialysis patients over 60 years old and identify the contributing factors.

METHODS

A group of elderly dialysis patients in the Department of Nephrology, Pan'an People's Hospital between March 2015 and June 2018 were chosen as the subjects for this study. Patients were divided into two groups, those with cognitive impairment and those with normal cognitive function. Results of their Montreal Cognitive Assessment (MoCA) scores, Controlled Oral Word Association Test (COWAT), Wechsler Adult Intelligence Scale Digit Span subtest (WDMS), and Stanford Diagnostic Math Test (SDMT) were reviewed and analyzed.

RESULTS

Among the 110 elderly dialysis patients, 75 patients (68.18%) showed different levels of damage to their cognitive function. Their assessment scores on MoCA (total), MoCA subtests: visuospatial/executive, naming, attention, language, delayed recall, abstraction and orientation, COWAT (total), COWAT1, COWAT2, COWAT3, WMDS-Backward, and SDMT are significantly lower than patients with normal cognitive abilities (p < 0.05). Further analysis showed that the highest percentage (72.00%) of patients had impairment with visuospatial/executive function; and, of the 75 cognitive impaired patients, 37.33% showed cognitive damage in two MoCA subtests simultaneously. Patients with and without cognitive impairment showed a significant (p < 0.05) difference on factors including age, education level, employment status, financial situation, dialysis vintage, serum albumin, and hemoglobin.

CONCLUSION

Elderly patients on dialysis have a higher risk of becoming cognitive impaired. The cognitive impairment in elderly dialysis patients was significantly associated with age, dialysis vintage, and levels of serum albumin and hemoglobin.

Prevalence of mild cognitive impairment in automated peritoneal dialysis patients

BACKGROUND

Cognitive deterioration decreases quality of life, self-care and adherence to treatment, increasing mortality risk. There is scarce information of cognitive impairment in peritoneal dialysis, and data are controversial.

OBJECTIVE

To determine the frequency and associated factors of cognitive impairment in patients on automated peritoneal dialysis (APD).

METHODS

Cross-sectional study; 71 patients on APD underwent clinical, biochemical and cognitive function evaluation by means of the Mini Mental State Examination (MMSE) and the Montreal Cognitive Assessment (MoCA). Cognitive function was also evaluated in healthy controls.

RESULTS

Mean age was 42 ± 16 years, 79% were men and dialysis vintage was 17 (7-32) months. In APD patients, cognitive impairment was present in 7% (mild deterioration) and 68% according to the MMSE and MoCA, respectively, and in 4% and 37% in the healthy controls. Patients with cognitive impairment (according to MoCA) were older, with lower educational degree, had more frequently diabetes, and higher serum glucose, as well as lower serum creatinine, phosphorus and sodium concentrations than patients with normal cognitive function. In multiple linear regression analysis, predictors for the MoCA score (R2 0.63, p = 0.002) were schooling [B = 0.54 (0.20 to 0.89), p = 0.003], age [B=-0.11 (-0.21 to -0.01), p = 0.04], serum sodium [B = 0.58 (0.05 to 1.11), p = 0.03] and creatinine concentrations [B = 3.9 (0.03 to 0.83), p = 0.03].

CONCLUSION

In this sample of APD patients with mean age in the early 40 s, the prevalence of cognitive impairment by MoCA test was 65%, and it was associated to older age, lower educational level and lower serum concentrations of sodium and creatinine.

Neurological effects of hemodialysis on white matter microstructure in end-stage renal disease

OBJECTIVES

To detect the effects of hemodialysis (HD) on the central nervous system (CNS), the present study forces the memory storage capacity and the difference in white matter (WM) microstructure characteristics among end-stage renal disease (ESRD) participants before HD initiation (ESRD-BHD), ESRD participants with maintenance HD (ESRD-MHD), and healthy participants (HCs).

METHODS

Between 2016 and 2018, 56 ESRD-BHD, 39 ESRD-MHD, and 56 HCs were recruited for this study. The fractional anisotropy (FA) of tractography streamlines within the working memory network was investigated using a novel along-tracts analysis method. The relationship between WM microstructure and working memory scores, measured from an n-back task, were detected by multiple correlation analysis.

RESULTS

As compared with HCs, a significantly lower FA was found along part of the WM in the working memory network in ESRD-BHD. In the group-difference location of ESRD-BHD and HCs, the FA of ESRD-MHD was reversed to normal levels in HCs. However, the FA in a new location was differentially reduced across groups: highest in HCs, intermediate in ESRD-BHD, and lowest in ESRD-MHD. Correlation analysis showed that a longer reaction time correlated to a lower FA, according to the following pattern: ESRD-BHD > ESRD-MHD > HCs.

CONCLUSION

Despite the persisting abnormal brain structure, our findings suggest HD has a neuroprotective effect in ESRD patients.

Clinical factors affecting cerebral oxygenation in patients undergoing peritoneal dialysis

BACKGROUND

Although cerebral regional oxygen saturation (rSO₂) is significantly lower in hemodialysis (HD) patients than that in healthy controls, investigations on cerebral oxygenation in peritoneal dialysis (PD) patients are limited. We aimed to confirm the cerebral oxygenation status and identify the factors affecting cerebral rSO₂ in PD patients.

METHODS

Thirty-six PD patients (21 men and 15 women; mean age, 62.8 ± 12.7 years) were recruited. In addition, 27 healthy volunteers (17 men and 10 women; mean age, 43.5 ± 18.8 years) were recruited as a control group. Cerebral rSO₂ was monitored at the forehead using an INVOS 5100c oxygen saturation monitor.

RESULTS

Cerebral rSO₂ was significantly lower in PD patients than that in healthy controls (57.0 ± 7.3% vs 68.9 ± 8.6%, p < 0.001); moreover, cerebral rSO₂ was significantly correlated with natural logarithm (Ln)-PD duration (r = -0.389, p = 0.019) and serum albumin concentration (r = 0.370, p = 0.026) in a simple linear regression analysis. Multivariable linear regression analysis was performed using variables that showed a significant correlation and p < 0.20 (serum creatinine, serum sodium, Ln-C-reactive protein, and dosage of erythropoiesis-stimulating agent) with the cerebral rSO₂. Cerebral rSO₂ was independently associated with Ln-PD duration (standardized coefficient: -0.339) and serum albumin concentration (standardized coefficient: 0.316).

CONCLUSIONS

Cerebral rSO₂ was significantly affected by the PD duration and serum albumin concentration. Further prospective studies are needed to clarify whether preventing a decrease in serum albumin concentration leads to the maintenance of cerebral oxygenation in patients undergoing PD.

Risk factors for sleep disorders in patients undergoing peritoneal dialysis

Sleep disorders in patients with end-stage renal disease are common but have rarely been reported in previous studies. Therefore, we examined the prevalence of sleep disorders and the risk factors for declining sleep quality in patients undergoing peritoneal dialysis (PD). A multicenter prospective cohort study was conducted at five PD centers across different provinces in China. A total of 449 patients who underwent PD between March to November 2013 were enrolled. Demographic data, laboratory indicators, presence of depression, and sleep assessment data were collected. Sleep questionnaires reflecting five categories of sleep disorders, namely, insomnia, restless legs syndrome, excessive daytime sleepiness, possible narcolepsy, and sleepwalking and nightmares, were administered at baseline and at 24 months postoperatively. Sleep disorders were diagnosed when a patient had at least one sleep problem. At baseline, 335 (74.6%) patients had at least one type of sleep disorder. Depression, diabetes mellitus (DM), and male were found to be associated with the presence of a sleep disorder. At follow-up, the prevalence of insomnia, restless legs syndrome, and excessive daytime sleepiness had significantly increased in 285 patients. Furthermore, cardiovascular disease (CVD) was found to be associated with the presence of sleep disorders in patients with one or more disorders at baseline, whereas a low serum albumin level was found to be associated with sleep disorders in patients without any sleep disorders at baseline. The prevalence of sleep disorders was relatively high among PD patients at baseline and increased afterthe2-year follow-up. Depression, DM, and male were associated with all sleep disorders at baseline. CVD was associated with the presence of a sleep disorder at baseline and worse sleep quality at the 2-year follow-up; whereas a low serum albumin level was associated with the risk of acquiring a sleep disorder at the 2-year follow-up among patients with normal sleep status at baseline.

Cognitive impairment, endothelial biomarkers and mortality in maintenance haemodialysis patients: a prospective cohort study

BACKGROUND

Haemodialysis (HD) patients have a high prevalence of cardiovascular disease risk factors as well as cognitive impairment. The objective of the present study was to evaluate the interrelationship between cognitive impairment, endothelium-related biomarkers and cardiovascular/non-cardiovascular mortality.

METHODS

A total of 216 outpatients were recruited from three centres in a dialysis network in Brazil between June 2016 and June 2019. Sociodemographic and clinical data were obtained by applying a patient questionnaire, reviewing medical records data and conducting patient interviews. Cognitive function was assessed using the Cambridge Cognitive Examination. Plasma endothelium-related biomarkers [syndecan-1, intercellular adhesion molecule-1 (ICAM-1), vascular cell adhesion protein-1 (VCAM-1) and angiopoietin-2 (AGPT2)] were measured. Patients were followed for 30 months. Cox proportional hazards regression models were used to assess the associations of the cognitive function scores and each endothelium-related biomarker with cardiovascular/non-cardiovascular mortality.

RESULTS

Cognitive function was associated with cardiovascular mortality {each standard deviation [SD] better cognitive score was associated with a 69% lower risk for cardiovascular mortality [hazard ratio (HR) 0.31 [95% confidence interval (CI) 0.17-0.58]} but not with non-cardiovascular mortality. Moreover, cognitive function was also correlated with all endothelial-related biomarkers, except VCAM-1. ICAM-1, AGPT2 and syndecan-1 were also associated with cardiovascular mortality. The association between cognitive function and cardiovascular mortality remained significant with no HR value attenuation [fully adjusted HR 0.32 (95% CI 0.16-0.59)] after individually including each endothelial-related biomarker in the Cox model.

CONCLUSIONS

In conclusion, cognitive impairment was associated with several endothelium-related biomarkers. Moreover, cognitive impairment was associated with cardiovascular mortality but not with non-cardiovascular mortality, and the association between cognitive impairment and cardiovascular mortality in HD patients was not explained by any of the endothelial-related biomarkers.

Interventions to Preserve Cognitive Functioning Among Older Kidney Transplant Recipients

PURPOSE OF REVIEW

To summarize the research on effective interventions for preserving cognitive function and prevent cognitive decline in patients with end-stage kidney disease (ESKD) who are undergoing dialysis and/or kidney transplantation (KT).

RECENT FINDINGS

Among ESKD patients undergoing hemodialysis, exercise training has been administered through home-based and intradialytic interventions. Additionally, one pilot study identified intradialytic cognitive training, electronic brain games, as an intervention to preserve cognitive function among patients undergoing hemodialysis. Fewer studies have investigated interventions to preserver cognitive function among KT recipients. To date, the only randomized controlled trial in this population identified B-vitamin supplements as an intervention to preserve cognitive function. The evidence from these trials support a short-term benefit of cognitive and exercise training as well as B-vitamin supplementation among patients with ESKD. Future studies should: 1) replicate these findings, 2) identify interventions specific to KT candidates, and 3) investigate the synergistic impact of both cognitive and exercise training.

SUMMARY

Cognitive prehabilitation, with cognitive and/or exercise training, may be novel interventions for KT candidates that not only reduces delirium risk and long-term post-KT cognitive decline but also prevents dementia.

Dialysis Modality and Mortality in Heart Failure: A Retrospective Study of Incident Dialysis Patients

INTRODUCTION

Prior studies reported lower mortality with hemodialysis (HD) compared to peritoneal dialysis (PD) in patients with heart failure (HF). We examined mortality rate by initial dialysis modality in incident dialysis patients with a history of HF using contemporary data and methods that ensure comparable HD and PD groups.

METHODS

Retrospective cohort study using administrative databases in Ontario, Canada. Adults (age 50-80) with a history of HF who initiated maintenance dialysis between April 1, 2007 and March 31, 2016 were included. We excluded patients typically ineligible for PD as an initial modality (dialysis start in hospital, dementia, long-term care facility residency). We determined the cause-specific hazard ratio (transplant as a competing event) between initial dialysis modality (HD vs. PD) and all-cause mortality using an intention-to-treat approach.

RESULTS

We included 2,199 patients with HF who initiated maintenance dialysis (77% HD and 23% PD). There were 1,152 (67.8%) and 340 (68.1%) mortality events over a median follow-up of 2.4 and 2.5 years in the HD and PD groups, respectively. Patients initiating HD versus PD was not associated with the mortality rate (adjusted hazard ratio 1.0, 95% CI 0.9-1.1). Similar results were seen in analyses censoring at modality switches and treating modality as time-varying.

CONCLUSIONS

We found no difference in mortality by initial dialysis modality. Our data support the current practice of selecting dialysis modality based on patient preference for patients with pre-existing HF.

Association between Dialysis Adequacy and Cognition in Patients with Peritoneal Dialysis

OBJECTIVE

Cognition of peritoneal dialysis patients is influenced by various factors including dialysis adequacy such as fractional urea clearance (Kt/V) and relative overhydration (RelOH). This study aimed to discover the potential contribution of dialysis adequacy to cognitive function in patients undergoing peritoneal dialysis.

METHODS

Fifty-nine patients undergoing peritoneal dialysis were recruited. Demographic information, comorbidities, and clinical lab findings were retrospectively collected, and dialysis adequacy was determined by the Kt/V and RelOH calculation. Cognition and depression were measured with Digit Symbol Substitution Test, Hopkins Verbal Learning Test, Wechsler memory scale (spatial span), Wisconsin Card Sorting Test, and Beck's depression inventory. Partial correlation test was used to explore the correlation of dialysis adequacy with cognitive function.

RESULTS

RelOH showed significant correlation with some of the Wisconsin Card Sorting test results. The categories achieved showed negative correlation (r=-0.32, p=0.02) and trials to complete first category showed positive correlation (r=0.31, p=0.02) with RelOH. Other tasks showed no significant correlation with RelOH. Kt/V.

CONCLUSION

Our study demonstrates that peritoneal dialysis adequacy, measured by RelOH, seems to be significantly correlated with the occurrence of cognitive impairment. The outcome suggests that RelOH may have the potential to clarify the role of cognitive impairment in peritoneal dialysis patients.

Associations between small and middle molecules clearance and the change of cognitive function in peritoneal dialysis

BACKGROUND

Uremic toxins have been suspected as potential contributors for cognitive impairment in peritoneal dialysis (PD) patients. However, associations between the clearance of serum small and middle molecules and the change of cognitive function were not fully explored and then we explored this issue in the present study.

METHOD

A total of clinically-stable 222 patients on PD were enrolled and then followed up for 2 years in this single-center prospective cohort study. Small and middle molecules clearances were examined by urea clearance (Kt/V), creatinine clearance (Ccr) and beta-2 microglobulin (B2M) clearance via dialysate and urine at baseline and after 2 years. Global and specific cognitive impairment were measured at baseline and after 2 years. Modified Mini-Mental State Examination (3MS) was assessed for global cognitive function, trail-making tests A and B for executive function and subtests of the battery for the assessment of neuropsychological status for immediate and delayed memory, visuospatial skills and language ability.

RESULTS

The median of total Kt/V, Ccr and B2M clearance were 1.89, 53.2 l/w/1.73 m2 and 17.5 l/w/1.73 m2, respectively at baseline. The prevalence of global cognitive impairment was 12.3% for 222 patients and 15.4% for the remained 130 patients after 2 years. At baseline, total Kt/V was independently positively associated with delayed memory function. Total and dialysate beta-2 microglobulin clearance was positively associated with 3MS scores and negatively with completion time on trail A after multivariate adjustment. At 2 years, we observed a significant difference in the changing trend of 3MS scores between groups divided by total B2M clearance (P = 0.033), which still maintained to be meaningful after multivariate adjustment (P = 0.024). Patients with total B2M clearance > 19.0 l/w/1.73 m2 got significant improvement on their 3MS scores (P = 0.005). Patients divided by total Kt/V or Ccr were not significantly different in the trends of general and any specific cognitive function during the follow up.

CONCLUSION

The higher middle molecules clearance independently correlated to better performance on general cognitive and executive function in PD patients, which also predict an improvement in general cognitive function during the follow up.

Operational considerations for peritoneal dialysis management during the COVID-19 pandemic

Background

Coronavirus disease 2019 (COVID-19) is an infectious respiratory disease caused by a novel coronavirus—severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). It is spread from human to human and has resulted in a global pandemic, posing a disastrous public health risk worldwide. Patients with chronic kidney disease, especially those on dialysis, are considered to be at higher risk of developing severe COVID-19 due to their immunocompromised status and frail condition. The home treatment setting of peritoneal dialysis (PD) has advantages in terms of implementing self-care when routine hospital visits and social activities are restricted, thus greatly reducing exposure of PD patients to the virus.

Methods and Results

We outline general operational considerations in PD management during the COVID-19 pandemic, including precautionary measures for PD patients and healthcare staff. Precautionary measures for PD patients include education on prevention of, and screening for, COVID-19, preclinic screening, in-clinic management, meticulous remote patient management and special hospitalization arrangements. The diagnosis and treatment of PD patients with COVID-19 are discussed. Precautionary measures for PD staff include continuous education on, and training in, COVID-19, exposure history surveillance and self-monitoring for COVID-19 among healthcare personnel, appropriate personal protective equipment and hand hygiene, organization of medical activities and staffing, and adequate environment cleaning.

Conclusions

This is a battle of the entire human society against the novel coronavirus. Integrated teamwork among healthcare providers, supported by society as a whole, is needed as part of the ongoing public health response to try to slow the spread of COVID-19.

The validation of the Beijing version of the Montreal Cognitive Assessment in Chinese patients undergoing hemodialysis

Objective

Cognitive impairment is common among hemodialysis patient, but still lack adequate screening in clinical settings. The Montreal Cognitive Assessment (MoCA) is reportedly to be a sensitive screening tool for cognitive impairment, but its clinical value in patients undergoing hemodialysis is not well established. We aimed to validate the utility of the Beijing version of the MoCA (MoCA-BJ) for detecting cognitive impairment in comparison to a detailed neuropsychological battery as the gold standard.

Methods

We assessed 613 patients undergoing hemodialysis using the MoCA-BJ, the Mini-Mental State Examination (MMSE), and a comprehensive neuropsychological battery. Cognitive dysfunction was defined by the fifth version of the Diagnostic and Statistical Manual of Mental Disorders (DSM-V). Spearman’s correlation and linear regression were used to estimate the performance of the MoCA-BJ and MMSE in predicting cognitive impairment. A receiver operating characteristic (ROC) curve analysis was used to evaluate the utility of various cutoffs of the MoCA-BJ and MMSE for predicting cognitive impairment.

Results

Cognitive impairment was diagnosed in 80.91% (496/613), 75.69% (464/613), and 61.34% (376 /613) of the patients using the DSM-V, MoCA-BJ, and MMSE, respectively. Spearman’s rank correlation analysis indicated that the MoCA-BJ was significantly correlated with the neuropsychological battery (r_s = 0.639, p<0.001), whereas the MMSE had a weaker correlation with the battery. The area under the ROC curve for cognitive impairment diagnosis using the MoCA-BJ was 0.891 (95% confidence interval: 0.859–0.924) while using the MMSE was 0.823 (95% confidence interval: 0.786–0.860). The optimal MoCA-BJ cutoff score in discriminating patients with and without cognitive impairment was 24 points with a sensitivity of 0.877 and specificity of 0.752.

Conclusion

The MoCA-BJ offers good sensitivity and specificity levels in detecting cognitive impairment in hemodialysis patients. These findings support the utility of the MoCA-BJ as a screening tool for cognitive impairment in Chinese patients undergoing hemodialysis.

Alterations in Structural and Functional Connectivities in Patients with End-Stage Renal Disease

Background and Purpose

The aim of this study was to evaluate the structural and functional connectivities of brain network using graph theoretical analysis in neurologically asymptomatic patients with end-stage renal disease (ESRD). We further investigated the prevalence of cognitive impairment (CI) in ESRD patients and analyzed the association between network measures of brain connectivity and cognitive function.

Methods

We prospectively enrolled 40 neurologically asymptomatic ESRD patients, 40 healthy controls, and 20 disease controls. All of the subjects underwent diffusion-tensor imaging (DTI) and resting-state functional magnetic resonance imaging (rs-fMRI). We calculated measures of structural and functional connectivities based on DTI and rs-fMRI, respectively, and investigated differences therein between the ESRD patients and the healthy controls. We assessed cognitive function in the ESRD patients using the Korean version of the Consortium to Establish a Registry for Alzheimer's Disease neuropsychological battery.

Results

The ESRD patients exhibited decreased global structural and functional brain connectivities, as well as alterations of network hubs compared to the healthy controls and disease controls. About 70% of the ESRD patients had CI. Moreover, ESRD patients without CI exhibited decreased global connectivity and alterations of network hubs. Furthermore, there was a significant positive association between measures of brain connectivity and cognitive function.

Conclusions

We found that ESRD patients exhibited decreased structural and functional brain connectivities, and that there was a significant association between brain connectivity and cognitive function. These alterations in the brain network may contribute to the pathophysiological mechanism of CI in ESRD patients.

Disentangling the multiple links between renal dysfunction and cerebrovascular disease

Chronic kidney disease (CKD) has a rapidly rising global prevalence, affecting as many as one-third of the population over the age of 75 years. CKD is a well-known risk factor for cardiovascular disease and, in particular, there is a strong association with stroke. Cohort studies and trials indicate that reduced glomerular filtration rate increases the risk of stroke by about 40% and that proteinuria increases the risk by about 70%. In addition, CKD is also strongly associated with subclinical cerebrovascular abnormalities, vascular cognitive impairment and dementia. The mechanisms responsible for these associations are currently unclear. CKD is associated with traditional risk factors such as hypertension, diabetes mellitus and atrial fibrillation, but non-traditional risk factors such as uraemia, oxidative stress, mineral and bone abnormalities, and dialysis-related factors, such as changes in cerebral blood flow or cardiac structure, are also postulated to play a role. Kidney disease can also impact and complicate the treatments used in acute stroke and in secondary prevention. In this review, we will outline our current understanding of the epidemiology and pathophysiology of cerebrovascular disease in CKD.

Sleep Disorders and Cognitive Impairment in Peritoneal Dialysis: A Multicenter Prospective Cohort Study

BACKGROUND

Patients with chronic kidney disease experience a high burden of sleep disorders, and there are associations between sleep disorders and cognitive impairment.

OBJECTIVES

Based on our previous cross-sectional survey on cognitive impairment in peritoneal dialysis, we further explored the relationship between sleep disorders and cognitive impairment, and predictors for declining cognitive function.

METHOD

We conducted a multicenter prospective cohort study enrolling 458 clinically stable patients on peritoneal dialysis who were then followed up for 2 years.Demographic data, comorbidities, depression, and biochemistry data were collected at baseline. Sleep disorders including insomnia, restless legs syndrome, sleep apnea syndrome, excessive daytime sleepiness, possible narcolepsy, sleep walking and nightmares, and possible rapid eye movement behavior disorders were assessed using a panel of specific sleep questionnaires at baseline and in a second survey. Global cognitive function was measured at baseline and in a second survey, using the Modified Mini-Mental State Examination. Specific cognitive domains were evaluated using Trail-Making Test Forms A and B for executive function, and subtests of the Battery for the Assessment of Neuropsychological Status were used to asses immediate and delayed memory, visuospatial skills, and language ability.

RESULTS

Sleep disorders were common among peritoneal dialysis patients. The prevalence of cognitive impairment evaluated by the Modified Mini-Mental State Examination (3MS) increased from 19.8 to 23.9%. Possible narcolepsy was associated with decreased Modified Mini-Mental State Examination scores at baseline. During follow-up, sleepwalking and nightmares were associated with higher risks of declined delayed memory in the longitudinal study.

CONCLUSIONS

Possible narcolepsy was associated with general cognitive dysfunction, and sleep walking and nightmares were risk factors for impaired delayed memory.

Depression at Baseline is an Independent Risk Factor for Cognitive Decline in Patients on Peritoneal Dialysis: A Multicenter Prospective Cohort Study

Background

Depression has been recognized as a risk factor for cognitive impairment (CI) from cross-sectional datasets. This multicenter prospective study investigated the association between depression and cognitive decline in peritoneal dialysis (PD) patients.

Methods

This multicenter prospective cohort study included 458 PD patients who were followed up for 2 years. The Modified Mini-Mental State Examination (3MS) was used for assessment of global cognitive function, Trail-Making Tests A and B for executive function, subtests of the Battery for the Assessment of Neuropsychological Status for immediate and delayed memory, visuospatial skill, and language ability. Depression was assessed using Zung's Self-Rating Depression Scale.

Results

During the 2-year follow-up, patients with moderate/severe depression at baseline showed a significant decline in global cognitive function (80.5 ± 15.2 vs 76.6 ± 15.5, p = 0.008), while patients without depression or with mild depression kept a stable global cognitive function. In the meantime, patients without depression showed significant improvements in immediate memory, visuospatial skill, and language ability. However, no significant improvement in these parameters was shown in depression groups. In multivariable linear regression analysis, depression at baseline was a significant predictor of worsening global cognitive function, whether depression was analyzed as a continuous variable (odds ratio [OR] = -0.14, 95% confidence interval [CI] -0.27, -0.01, p = 0.031) or a rank variable (OR = -1.88, 95% CI -3.30, -0.45, p = 0.010). Moreover, higher depression score or more severe depression degradation was significantly associated with decline of immediate memory, delayed memory, and language skill.

Conclusion

Depression was a significant risk factor for worsening of CI in PD patients.

Quality of Life of Couples Living with Sarcoidosis

BACKGROUND

Consequences of sarcoidosis are wide ranging, and the symptom burden has a great impact on patients' quality of life (QoL). However, the QoL of couples living with sarcoidosis has not yet been studied.

OBJECTIVES

Our aim was to assess the QoL of couples living with sarcoidosis and to evaluate whether living with a partner with sarcoidosis influences the partner's QoL. Furthermore, we aimed to assess whether nonspecific symptoms (fatigue, cognitive failure, small fiber neuropathy (SFN)-related symptoms, depressive symptoms, and state/trait anxiety) predict QoL of partners as well as sarcoidosis patients.

METHOD

Sarcoidosis outpatients, recruited at Maastricht University Medical Centre (n = 443), and their partners (n = 208) completed several questionnaires, including the World Health Organization QoL - BREF, Fatigue Assessment Scale, SFN screening list, and cognitive failure questionnaire.

RESULTS

QoL of the partners as well as the sarcoidosis patients was reduced compared with healthy controls, especially regarding the physical health domain. All nonspecific symptoms studied, as well as perceived social support, predicted one or more QoL domains in the sarcoidosis patients, but these factors did not predict the QoL of their partners.

CONCLUSIONS

The QoL of partners of sarcoidosis patients was reduced, although to a lesser extent than that of the patients. Although the nonspecific symptoms and perceived social support were related to the patients' QoL, this was not the case for the partners. In the management of sarcoidosis, it is important to focus not only on the patients but also on their partners.

Exercise and cognitive function in patients with end-stage kidney disease

In this review we summarize the research pertaining to the role of exercise in preventing cognitive decline in patients with end-stage kidney disease (ESKD). Impairment in cognitive function, especially in executive function, is common in patients with ESKD, and may worsen with maintenance dialysis as a result of retention of uremic toxins, recurrent cerebral ischemia, and high burden of inactivity. Cognitive impairment may lead to long-term adverse consequences, including dementia and death. Home-based and intradialytic exercise training (ET) are among the nonpharmacologic interventions identified to preserve cognitive function in ESKD. Additionally, cognitive training (CT) is an effective approach recently identified in this population. While short-term benefits of ET and CT on cognitive function were consistently observed in patients undergoing dialysis, more studies are needed to replicate these findings in diverse populations including kidney transplant recipients with long-term follow-up to better understand the health and quality of life consequences of these promising interventions. ET as well as CT are feasible interventions that may preserve or even improve cognitive function for patients with ESKD. Whether these interventions translate to improvements in quality of life and long-term health outcomes, including dementia prevention and better survival, are yet to be determined.

[Association of malnutrition-inflammation-cardiovascular disease with cognitive deterioration in peritoneal dialysis patients]

OBJECTIVE

To investigate the relationship between malnutrition-inflammation-atherosclerosis (MIA) syndrome and deterioration of global and specific domains of cognitive function in peritoneal dialysis (PD) patients.

METHODS

This was a multi-center prospective cohort study. The PD patients who met the inclusion criteria were examined with general and specific cognitive function between March 2013 and November 2013. The patients were divided into MIA0, MIA1 and MIA2 groups, according to items of "Yes" for whether or not having cardiovascular disease, serum albumin≤35 g/L or high-sensitive C-reactive protein (hs-CRP) ≥3 mg/L. After 2 years, the patients maintained on PD would be repeatedly measured with cognitive function. The Chi-square test, One-way ANOVA, Kruskal-wallis H rank sum test were used to compare the differences of clinical characteristics, biochemical data, and global and specific cognitive function parameters among the three groups at baseline, and two years later, respectively. The Bonferroni method was applied to adjust the significance level for further comparison between each two different groups. The change of score in each cognitive parameter of global and specific domains was used as dependent variable. Age, gender, education level, depression index, body-mass index, diabetes mellitus, serum sodium levels and MIA (MIA0 was control, MIA1 and MIA2 as dummy variables) were all included in the multivariable linear regression models to analyze the risk factors of the deterioration of cognitive function. The analysis for each cognitive domain was adjusted for the baseline score of the corresponding cognitive parameter. All the analyses were performed using SPSS for Windows, software version 25.0 (SPSS Inc., Chicago, IL).

RESULTS

Over two-year follow up, the prevalence of cognitive impairment increased from 20.0% to 24.7%, absolute decrease of 3MS scores were more significantly decreased in MIA2 (-3.9±12.0 vs. 1.1±6.7, P<0.01) and MIA1 group (-2.3±11.8 vs. 1.1±6.7, P<0.05) than those in MIA0 group respectively. Specific cognitive functions, included executive function (trail-making tests A and B, P=0.401, P=0.176), immediate memory (P=0.437), delayed memory (P=0.104), visuospatial skill (P=0.496), and language ability (P=0.171) remained unchanged. Advanced age, lower education, diabetes mellitus and depression were all correlated with the deterioration of one or more cognitive domains, and the patients having one item of MIA syndrome were prone to develop the deterioration of 3MS (P=0.022). Furthermore, the patients having two or more items of MIA syndrome were more likely to develop the deterioration of not only 3MS (P <0.001), but also delayed memory, visuospatial skill, and language ability (P=0.002, P=0.007, P=0.004, respectively).

CONCLUSION

Patients with one item or above of MIA syndrome were at high-risk for the deterioration of global cognitive function. The more MIA syndrome items there were, the more specific cognitive domains deteriorated.