Overview of the findings and advances in the neurocognitive and psychosocial functioning of mild to moderate pediatric CKD: perspectives from the Chronic Kidney Disease in Children (CKiD) cohort study

Investigation of a targeted panel of gut microbiome-derived toxins in children with chronic kidney disease

BACKGROUND

The gut-kidney axis is implicated in chronic kidney disease (CKD) morbidity. We describe how a panel of gut microbiome-derived toxins relates to kidney function and neurocognitive outcomes in children with CKD, consisting of indoleacetate, 3-indoxylsulfate, p-cresol glucuronide, p-cresol sulfate, and phenylacetylglutamine.

METHODS

The Chronic Kidney Disease in Children (CKiD) cohort is a North American multicenter prospective cohort that enrolled children aged 6 months to 16 years with estimated glomerular filtration rate (eGFR) 30-89 ml/min/1.73 m2. Data from the 2-year study visit were used for this analysis. Toxin quantification (Metabolon Inc., Durham, NC) was performed with ultra-high performance liquid chromatography/tandem mass spectrometry. Executive function and echocardiograms were assessed. Regression analysis examined the association of toxin levels with eGFR, CKD etiology, and neurocognitive and cardiac assessments (adjusted for age, sex, and urine protein:creatinine [UPCR]).

RESULTS

There were 150 CKiD participants included in this study. All toxins levels were significantly inversely correlated with eGFR (Spearman's rho - 0.45 to - 0.69). Children with non-glomerular CKD had significantly higher levels of 3-indoxylsulfate, phenylacetylglutamine, and p-cresol glucuronide. The toxin levels did not associate with neurocognitive outcomes. P-cresol glucuronide and phenylacetylglutamine negatively associated with left ventricular mass index z score, but did not associate with left ventricular hypertrophy.

CONCLUSIONS

Children with CKD have high levels of circulating gut microbiome-derived toxins. The levels of these toxins are strongly correlated with eGFR. There appear to be differences in toxin level based on glomerular versus non-glomerular etiology, even when accounting for the differences in eGFR between these two subgroups. In this sample, we did not detect any associations between these toxin levels and neurocognitive or cardiac outcomes.

Neurocognitive disruption in pediatric kidney transplant candidates: Medical and sociodemographic factors

We evaluated the effects of kidney failure etiology, dialysis, and area deprivation index on the subdomains of neurocognitive functioning in pediatric kidney transplant candidates. The study included 78 pediatric kidney transplant candidates (47.4% male, 70.5% White, M.age = 11.77 years, and 51.3% patients have public insurance) who completed a pre-transplant neuropsychological evaluation between 1/1/2010 and 10/31/2022. Linear regression models were employed to complete data analyses. The mean scores of various neurocognitive functioning domains in pediatric kidney transplant candidates were significantly lower than in the general population (ps < .001). After adjusting for covariates, patients with congenital anomalies of the kidney and urinary tract (M = 87; 95% CI: 80-94) and other etiologies (M = 82; 95% CI: 76-89) had significantly lower processing speed compared to patients with nephrotic syndrome (M = 98; 95% CI: 89-107) (p = .02). Patients living in high-level deprivation neighborhoods showed significantly lower verbal skills (p = .01), working memory performance (p = .02), and full-scale IQ (p = .03) than patients living in median-level and low-level deprivation neighborhoods. Additionally, dialysis did not show significant association with neurocognitive domains ((ps ranged from .07 to .52).

Family Environment, Social Support, and Health-Related Quality of Life in Adolescents Following Kidney Transplant

BACKGROUND

Kidney transplantation is the treatment of choice for pediatric end-stage renal disease. Transplant recipients often have better neurocognitive, academic, and health-related outcomes. While there is some evidence that health-related quality of life (HRQOL) improves following kidney transplant, other studies have found adolescent transplant recipients report lower overall HRQOL than healthy peers. Current research has focused on individual-level factors affecting adjustment to organ transplant, warranting examination of HRQOL from a systems perspective. Family environment and social support contribute to a system of proximal relationships that are crucial in adolescents' development, making them important factors to study in relation to HRQOL post-transplant.

METHODS

The current study utilized archival data of adolescent renal transplant patients who completed surveys about their family environment, social support, and HRQOL during routine transplant clinic visits.

RESULTS

Family cohesion, as well as social support from parents, classmates, and people in school, were positively correlated with HRQOL. Social support from people in school uniquely predicted variance in HRQOL, beyond the contribution of overall family environment after controlling for demographic factors. Relative to comparable adolescent samples, transplant recipients reported more optimal overall family environment, greater social support from teachers, and lower social support from close friends.

CONCLUSION

Psychosocial interventions for adolescent kidney transplant recipients may be enhanced by collaborating with school professionals and further bolstering strengths in the family environment. Kidney transplant recipients may benefit from long-term intervention, as decreased HRQOL appears to persist years post-transplant.

Neurocognitive Profile in Pediatric Kidney Transplant Candidates: Effects of Medical and Sociodemographic Factors

Background

We evaluated the effects of kidney failure etiology, dialysis, and sociodemographic factors on the subdomains of intellectual functioning in pediatric kidney transplant candidates.

Methods

This retrospective study included 78 pediatric kidney transplant candidates who completed a Wechsler Intelligence Scale assessment during pre-transplant neuropsychological evaluation between 1/1/2010 and 10/31/2022. Linear regression models were employed to examine the effects of kidney failure etiology, dialysis status, neighborhood area deprivation, and race on subdomains of intellectual functioning.

Results

The mean scores of various intellectual functioning domains in pediatric kidney transplant candidates were significantly lower than in the general population (ps <0.001). After adjusting for covariates, patients with congenital anomalies of the kidney and urinary tract had significantly lower processing speed (M=85; 95% CI: 79-91) compared to patients with nephrotic syndrome (M=99; 95% CI: 90-107) and other etiologies (M=84; 95% CI: 78-90) (p=0.003). Patients living in high-level deprivation neighborhoods showed lower working memory performance (M=84, 95% CI: 77-91) than patients living in median-level (M=91, 95% CI: 87-95) and low-level (M=98, 95% CI: 92-104) neighborhood area deprivation (p=0.03). Patients from marginalized racial groups demonstrated lower verbal skills (M=80, 95% CI: 74-87) than White patients (M=92, 95% CI: 88-97) (p=0.02). Additionally, patients receiving dialysis showed higher reasoning skills (M=98, 95% CI: 90-104) than patients without dialysis (M= 90, 95% CI: 86-95) (p=0.04).

Conclusions

Neurocognitive development in pediatric kidney transplant candidates is associated with medical and sociodemographic factors. Strategies to monitor, treat, and accommodate neurocognitive concerns need to be considered to optimize long-term medical and social outcomes.

Socioeconomic Position and Health Among Children and Adolescents With CKD Across the Life-Course

Children and adolescents in families of lower socioeconomic position (SEP) experience an inequitable burden of reduced access to healthcare and poorer health. For children living with chronic kidney disease (CKD), disadvantaged SEP may exacerbate their considerable disease burden. Across the life-course, CKD may also compromise the SEP of families and young people, leading to accumulating health and socioeconomic disadvantage. This narrative review summarizes the current evidence on relationships of SEP with kidney care and health among children and adolescents with CKD from a life-course approach, including impacts of family SEP on kidney care and health, and bidirectional impacts of CKD on SEP. It highlights relevant conceptual models from social epidemiology, current evidence, clinical and policy implications, and provides directions for future research. Reflecting the balance of available evidence, we focus primarily on high-income countries (HICs), with an overview of key issues in low- and middle-income countries (LMICs). Overall, a growing body of evidence indicates sobering socioeconomic inequities in health and kidney care among children and adolescents with CKD, and adverse socioeconomic impacts of CKD. Dedicated efforts to tackle inequities are critical to ensuring that all young people with CKD have the opportunity to live long and flourishing lives. To prevent accumulating disadvantage, the global nephrology community must advocate for local government action on upstream social determinants of health; and adopt a life-course approach to kidney care that proactively identifies and addresses unmet social needs, targets intervening factors between SEP and health, and minimizes adverse socioeconomic outcomes across financial, educational and vocational domains.

Circulating Metabolomic Associations with Neurocognitive Outcomes in Pediatric CKD

BACKGROUND

Children with CKD are at risk for impaired neurocognitive functioning. We investigated metabolomic associations with neurocognition in children with CKD.

METHODS

We leveraged data from the Chronic Kidney Disease in Children (CKiD) study and the Neurocognitive Assessment and Magnetic Resonance Imaging Analysis of Children and Young Adults with Chronic Kidney Disease (NiCK) study. CKiD is a multi-institutional cohort that enrolled children aged 6 months to 16 years with eGFR 30-90 ml/min per 1.73 m 2 ( n =569). NiCK is a single-center cross-sectional study of participants aged 8-25 years with eGFR<90 ml/min per 1.73 m 2 ( n =60) and matched healthy controls ( n =67). Untargeted metabolomic quantification was performed on plasma (CKiD, 622 metabolites) and serum (NiCK, 825 metabolites) samples. Four neurocognitive domains were assessed: intelligence, attention regulation, working memory, and parent ratings of executive function. Repeat assessments were performed in CKiD at 2-year intervals. Linear regression and linear mixed-effects regression analyses adjusting for age, sex, delivery history, hypertension, proteinuria, CKD duration, and glomerular versus nonglomerular diagnosis were used to identify metabolites associated with neurocognitive z-scores. Analyses were performed with and without adjustment for eGFR.

RESULTS

There were multiple metabolite associations with neurocognition observed in at least two of the analytic samples (CKiD baseline, CKiD follow-up, and NiCK CKD). Most of these metabolites were significantly elevated in children with CKD compared with healthy controls in NiCK. Notable signals included associations with parental ratings of executive function: phenylacetylglutamine, indoleacetylglutamine, and trimethylamine N-oxide-and with intelligence: γ -glutamyl amino acids and aconitate.

CONCLUSIONS

Several metabolites were associated with neurocognitive dysfunction in pediatric CKD, implicating gut microbiome-derived substances, mitochondrial dysfunction, and altered energy metabolism, circulating toxins, and redox homeostasis.

PODCAST

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Depression in Children and Adolescents with Chronic Kidney Disease-Review of Available Literature

Depression is a significant health problem gaining increasing relevance, especially among children and adolescents. It is known that the incidence of depression is higher in patients suffering from chronic diseases, such as chronic kidney disease (CKD). This review aims to discuss the prevalence of depression in children and adolescents with CKD and its impact on the quality of life of these patients (HRQoL). The research was conducted using online databases with keywords: depression in children and adolescents, depression and chronic diseases, chronic kidney disease, and health-related quality of life. It was found that the risk for developing depression is higher for adolescents and females, and with the use of negative coping strategies, lack of caregiver nurturance, and poor socioeconomic status. In patients with pediatric CKD, the stage of the disease, age of CKD diagnosis, and type of treatment were found to significantly impact HRQoL and contribute to caregiver burden. Depression was more commonly found in children suffering from CKD. It causes significant mental distress to the child and contributes to the caregiver's burden. Screening for depression among CKD patients is advised. In depressed patients, transdiagnostic tools should be used to alleviate some of the symptoms. In children at risk of developing depression, preventative strategies should be considered.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Chronic Kidney Disease in Children

Chronic kidney disease (CKD) in children occurs mostly due to congenital anomalies of kidney and urinary tract and hereditary diseases. For advanced cases, a multidisciplinary team is needed to manage nutritional requirements and complications such as hypertension, hyperphosphatemia, proteinuria, and anemia. Neurocognitive assessment and psychosocial support are essential. Maintenance dialysis in children with end-stage renal failure has become the standard of care in many parts of the world. Children younger than 12 years have 95% survival after 3 years of dialysis initiation, whereas the survival rate for children aged 4 years or younger is about 82% at one year."

Differential Attention Functioning in Pediatric Chronic Kidney Disease

Objective

To compare specific attention functions for school-age children with chronic kidney disease (CKD) to those of a typically developing control group.

Methods

A cross-sectional study examined attention dimensions for children and adolescents with CKD (n = 30) in comparison to a typically developing control group (n = 41). The CKD group consisted of those receiving maintenance dialysis (n = 15) and those with mild/moderate CKD treated conservatively (n = 15). Measures aligning with Mirsky’s conceptual multidimensional model of attention were selected to compare groups across five dimensions of attention: Focus/Execute, Sustain, Stability, Shift, and Encode.

Results

Significant group differences were revealed, with the CKD group performing worse than controls on the Focus/Execute, Sustain, and Encode dimensions. The CKD group also had a larger proportion of children with scores one standard deviation or more below the mean on the Shift and Encode domains, suggesting an at-risk level of functioning in these dimensions. Secondary analyses showed disease severity to be correlated with worse attention functions for children with CKD.

Conclusion

Children with CKD may be vulnerable to subtle, specific deficits in numerous attention dimensions relative to their typically developing peers, particularly for those with more severe disease.

The Similarities and Differences Between Glomerular vs. Non-glomerular Diagnoses on Intelligence and Executive Functions in Pediatric Chronic Kidney Disease: A Brief Report

Pediatric chronic kidney disease (CKD) appears to be a heterogeneous group of conditions, but this heterogeneity has not been explored with respect to its impact on neurocognitive functioning. This study investigated the neurocognitive functioning of those with glomerular (G) vs. non-glomerular (NG) diagnoses. Data from the North American CKiD Study were employed and the current study included 1,003 children and adolescents with mild to moderate CKD. The G Group included 260 participants (median age = 14.7 years) and the NG Group included 743 individuals (median age = 9.0 years). Neurocognitive measures assessed IQ, inhibitory control, attention regulation, problem solving, working memory, and overall executive functioning. Data from all visits were included in the linear mixed model analyses. After adjusting for sociodemographic and CKD-related covariates, results indicated no differences between the diagnostic groups on measures of IQ, problem solving, working memory, and attention regulation. There was a trend for the G group to receive better parent ratings on their overall executive functions (p < 0.07), with a small effect size being present. Additionally, there was a significant G group X hypertension interaction (p < 0.003) for inhibitory control, indicating that those with both a G diagnosis and hypertension performed more poorly than the NG group with hypertension. These findings suggest that the separation of G vs. NG CKD produced minimal, but specific group differences were observed. Ongoing examination of the heterogeneity of pediatric CKD on neurocognition, perhaps at a different time point in disease progression or using a different model, appears warranted.

Functional Magnetic Resonance Imaging Findings in Children and Adolescents With Chronic Kidney Disease: Preliminary Findings

This cross-sectional study provides preliminary findings from one of the first functional brain imaging studies in children with chronic kidney disease (CKD). The sample included 21 children with CKD (ages, 14.4 ± 3.0 y) and 11 healthy controls (ages, 14.5 ± 3.4 y). Using functional magnetic resonance imaging during a visual-spatial working memory task, findings showed that the CKD group and healthy controls invoked similar brain regions for encoding and retrieval phases of the task, but significant group differences were noted in the activation patterns for both components of the task. For the encoding phase, the CKD group showed lower activation in the posterior cingulate, anterior cingulate, precuneus, and middle occipital gyrus than the control group, but more activation in the superior temporal gyrus, middle frontal gyrus, middle temporal gyrus, and the insula. For the retrieval phase, the CKD group showed underactivation for brain systems involving the posterior cingulate, medial frontal gyrus, occipital lobe, and middle temporal gyrus, and greater activation than the healthy controls in the postcentral gyrus. Few group differences were noted with respect to disease severity. These preliminary findings support evidence showing a neurologic basis to the cognitive difficulties evident in pediatric CKD, and lay the foundation for future studies to explore the neural underpinnings for neurocognitive (dys)function in this population.

The Association of Aspartate Aminotransferase/Alanine Aminotransferase Ratio with Diabetic Nephropathy in Patients with Type 2 Diabetes

PURPOSE

To investigate the relationship between aspartate aminotransferase to alanine aminotransferase ratio (AST/ALT) and diabetic nephropathy (DN).

PATIENTS AND METHODS

A total of 402 patients with type 2 diabetes mellitus were divided into three groups, such as normoalbuminuria (n = 196), microalbuminuria (n = 131) and macroalbuminuria (n = 75) groups. Basic information and laboratory results were collected. Serum AST/ALT, tumor necrosis factor-α (TNF-α), interleukin (IL)-2, IL-4, IL-6, IL-10 and interferon- γ (INF- γ) were also measured. DN was defined as microalbuminuria or macroalbuminuria. The estimated glomerular filtration rate (eGFR) was calculated using the following formula: 186 × (serum creatinine)^-1.154× (age)^-0.203× (0.742 if female).

RESULTS

The AST/ALT in the macroalbuminuria group was higher than in the microalbuminuria and normoalbuminuria groups. The concentrations of tumor necrosis factor-α (TNF-α), IL-2, IL-4, IL-10 and INF-γ in the macroalbuminuria group were significantly higher than those in the two other groups. Multivariate logistical analysis showed that after adjusting confounding factors, TNF-α and high AST/ALT were independent risks for DN and macroalbuminuria. Furthermore, the AST/ALT had significantly positive correlation with TNF-α (r = 0.101, P = 0.048), IL-4 (r = 0.185, P = 0.005) and IL-6 (r = 0.274, P < 0.001) levels.

CONCLUSION

This study showed that high AST/ALT was an independent risk factor for the DN. Additionally, AST/ALT was positively correlated with inflammation cytokines, such as TNF-α, IL-4 and IL-6 levels.