Patient, Parental, and Health Professional Perspectives on Growth in Children With CKD.

RATIONALE & OBJECTIVE: Growth failure is a common problem among children with chronic kidney disease (CKD). Reduced height is associated with psychosocial burden, social stigma, and impaired quality of life. This study aimed to describe the aspects of growth impairment that are most impactful from the perspectives of children with CKD, their parents, and health professionals. STUDY DESIGN: Qualitative study. SETTINGS & PARTICIPANTS: 120 children with CKD (aged 8-21 years), 250 parents, and 445 health professionals from 53 countries participated in 16 focus groups, two consensus workshops, and a Delphi survey. ANALYTICAL APPROACH: A thematic analysis of all qualitative data concerning growth from the Standardized Outcomes in Nephrology - Children and Adolescents (SONG-Kids) initiative. RESULTS: We identified five themes: diminishing psychological wellbeing (compared to and judged by peers, tired of explaining to others, damaging self-esteem), constrained life participation and enjoyment (deprived of normal school experiences, excluded from sports or competing at a disadvantage, impaired quality of life in adulthood); grappling with impacts of symptoms and treatment (difficulty understanding short stature and accessing help, lack of appetite, uncertainty regarding bone pains, medication side effects, burden of growth hormone treatment); facilitating timely interventions and optimizing outcomes (early indicator of disease, assessing management, maximizing transplant outcomes, minimizing morbidity); and keeping growth and health priorities in perspective (quality of life and survival of utmost priority, achieved adequate height). LIMITATIONS: Only English-speaking participants were included. CONCLUSIONS: Impaired growth may diminish psychological wellbeing, self-esteem, and participation in daily activities for children with CKD. Balancing different treatments that can affect growth complicates decision-making. These findings may inform the psychosocial support needed by children with CKD and their caregivers to address concerns about growth.

Vitamin D and its associations with blood pressure in the Chronic Kidney Disease in Children (CKiD) cohort.

BACKGROUND: Vitamin D (25OHD) can modulate pathways and mechanisms that regulate blood pressure (BP). Observational studies in children and adults have shown an inverse association between 25OHD and BP. Studies evaluating associations between 25OHD and BP in pediatric chronic kidney disease are limited. METHODS: We evaluated the associations between 25OHD and BP using data from the Chronic Kidney Disease in Children (CKiD) study. Clinic or ambulatory BP index was defined as participant's BP divided by 95th age-sex-height-specific BP percentile, an index > 1 suggests hypertension. Primary outcomes of interest were changes in systolic and diastolic clinic and ambulatory BP indices over follow-up. Linear mixed-effects models were used to evaluate associations between BP indices and 25OHD. RESULTS: The study cohort consisted of 370 participants who contributed 970 person-visits. A subset of 194 participants with ambulatory BP data contributed 465 person-visits. There was an association between baseline 25OHD levels and clinic systolic BP index such that for every 10 ng/ml lower 25OHD, clinic systolic BP index was 1.0% higher (95%CI: 0.2-1.8, p = 0.016) between participants. The association between clinic diastolic BP index with baseline 25OHD was not significant. For within-person changes, longitudinal decreases in 25OHD were not significantly associated with concomitant increases in clinic systolic or diastolic BP index. There were no significant associations between 25OHD levels at baseline or longitudinally with 24-h ABPM indices. CONCLUSIONS: Low 25OHD levels were associated with higher clinic systolic BP in children with CKD. Vitamin D supplementation to maintain normal 25OHD levels might be a useful adjunctive treatment in optimizing BP control in these high-risk patients.

Antihypertensive medication nonadherence and target organ damage in children with chronic kidney disease.

BACKGROUND: Nonadherence is common in children with chronic kidney disease (CKD). This may contribute to inadequate blood pressure control and adverse outcomes. This study examined associations between antihypertensive medication nonadherence, ambulatory blood pressure monitoring (ABPM) parameters, kidney function, and cardiac structure among children with CKD. METHODS: We performed secondary analyses of data from the CKD in Children (CKiD) study, including participants with treated hypertension who underwent ABPM, laboratory testing, and echocardiography biannually. Nonadherence was defined by self-report of any missed antihypertensive medication 7 days prior to the study visit. Linear regression and mixed-effects models were used to assess the association of nonadherence with baseline and time-updated ABPM profiles, estimated glomerular filtration rate (eGFR), urine protein to creatinine ratio (UPCR), and left ventricular mass index (LVMI). RESULTS: Five-hundred and eight participants met inclusion criteria, followed for a median of 2.9 years; 212 (42%) were female, with median age 13 years (IQR 10-16), median baseline eGFR 49 (33-64) ml/min/1.73 m2 and median UPCR 0.4 (0.1-1.0) g/g. Nonadherence occurred in 71 (14%) participants. Baseline nonadherence was not significantly associated with baseline 24-h ABPM parameters (for example, mean 24-h SBP [ß - 0.1, 95% CI - 2.7, 2.5]), eGFR (ß 1.0, 95% CI - 0.9, 1.2), UCPR (ß 1.1, 95% CI - 0.8, 1.5), or LVMI (ß 0.6, 95% CI - 1.6, 2.9). Similarly, there were no associations between baseline nonadherence and time-updated outcome measures. CONCLUSIONS: Self-reported antihypertensive medication nonadherence occurred in 1 in 7 children with CKD. We found no associations between nonadherence and kidney function or cardiac structure over time. A higher resolution version of the Graphical abstract is available as Supplementary information.

A Drosophila model to screen Alport syndrome COL4A5 variants for their functional pathogenicity.

Alport syndrome is a hereditary chronic kidney disease, attributed to rare pathogenic variants in either of three collagen genes (COL4A3/4/5) with most localized in COL4A5. Trimeric type IV Collagen α3α4α5 is essential for the glomerular basement membrane that forms the kidney filtration barrier. A means to functionally assess the many candidate variants and determine pathogenicity is urgently needed. We used Drosophila, an established model for kidney disease, and identify Col4a1 as the functional homolog of human COL4A5 in the fly nephrocyte (equivalent of human podocyte). Fly nephrocytes deficient for Col4a1 showed an irregular and thickened basement membrane and significantly reduced nephrocyte filtration function. This phenotype was restored by expressing human reference (wildtype) COL4A5, but not by COL4A5 carrying any of three established pathogenic patient-derived variants. We then screened seven additional patient COL4A5 variants; their ClinVar classification was either likely pathogenic or of uncertain significance. The findings support pathogenicity for four of these variants; the three others were found benign. Thus, demonstrating the effectiveness of this Drosophila in vivo kidney platform in providing the urgently needed variant-level functional validation.

Consistency of metabolite associations with measured glomerular filtration rate in children and adults.

Background: There is interest in identifying novel filtration markers that lead to more accurate GFR estimates than current markers (creatinine and cystatin C) and are more consistent across demographic groups. We hypothesize that large-scale metabolomics can identify serum metabolites that are strongly influenced by glomerular filtration rate (GFR) and are more consistent across demographic variables than creatinine, which would be promising filtration markers for future investigation. Methods: We evaluated the consistency of associations between measured GFR (mGFR) and 887 common, known metabolites quantified by an untargeted chromatography- and spectroscopy-based metabolomics platform (Metabolon) performed on frozen blood samples from 580 participants in Chronic Kidney Disease in Children (CKiD), 674 participants in Modification of Diet in Renal Disease (MDRD) Study and 962 participants in African American Study of Kidney Disease and Hypertension (AASK). We evaluated metabolite-mGFR correlation association with metabolite class, molecular weight, assay platform and measurement coefficient of variation (CV). Among metabolites with strong negative correlations with mGFR (r < -0.5), we assessed additional variation by age (height in children), sex, race and body mass index (BMI). Results: A total of 561 metabolites (63%) were negatively correlated with mGFR. Correlations with mGFR were highly consistent across study, sex, race and BMI categories (correlation of metabolite-mGFR correlations between 0.88 and 0.95). Amino acids, carbohydrates and nucleotides were more often negatively correlated with mGFR compared with lipids, but there was no association with metabolite molecular weight, liquid chromatography/mass spectrometry platform and measurement CV. Among 114 metabolites with strong negative associations with mGFR (r < -0.5), 27 were consistently not associated with age (height in children), sex or race. Conclusions: The majority of metabolite-mGFR correlations were negative and consistent across sex, race, BMI and study. Metabolites with consistent strong negative correlations with mGFR and non-association with demographic variables may represent candidate markers to improve estimation of GFR.

Trials and Tribulations - The Challenges of Clinical Trials in Children.

In this issue of NEJM Evidence, we see the results of a randomized clinical trial of dapagliflozin or saxagliptin in pediatric type 2 diabetes (T2D). In children and adolescents with T2D, dapagliflozin achieved significant improvements in glycemia in the trial.1 In June 2023, following another pivotal trial, the U.S. Food and Drug Administration (FDA) approved empagliflozin and the combination of empagliflozin and metformin as additions to diet and exercise to improve blood sugar control in children 10 years and older with T2D. Metformin, the only other oral therapy available for the treatment of children with T2D, was first approved for pediatric use in 2000.

Obesity and kidney disease: hidden consequences of the epidemic / Obesidade e doença renal: consequências ocultas da epidemia

Abstract Obesity has become a worldwide epidemic, and its prevalence has been projected to grow by 40% in the next decade. This increasing prevalence has implications for the risk of diabetes, cardiovascular disease and also for Chronic Kidney Disease. A high body mass index is one of the strongest risk factors for new-onset Chronic Kidney Disease. In individuals affected by obesity, a compensatory hyperfiltration occurs to meet the heightened metabolic demands of the increased body weight. The increase in intraglomerular pressure can damage the kidneys and raise the risk of developing Chronic Kidney Disease in the long-term. The incidence of obesity-related glomerulopathy has increased ten-fold in recent years. Obesity has also been shown to be a risk factor for nephrolithiasis, and for a number of malignancies including kidney cancer. This year the World Kidney Day promotes education on the harmful consequences of obesity and its association with kidney disease, advocating healthy lifestyle and health policy measures that makes preventive behaviors an affordable option.

Resumo A obesidade tornou-se uma epidemia mundial, e foi projetado que sua prevalência irá crescer em 40% na próxima década. Esta crescente prevalência tem implicações para com o risco de diabetes, doenças cardiovasculares e também para a doença renal crônica. Um índice de massa corporal elevado é um dos mais fortes fatores de risco para o desenvolvimento de doença renal crônica. Em indivíduos afetados pela obesidade ocorre uma hiperfiltração compensatória, para atender às elevadas exigências metabólicas do aumento de peso corporal. O aumento da pressão intraglomerular pode prejudicar os rins e aumentar o risco do desenvolvimento de doença renal crônica a longo prazo. A incidência de glomerulopatia relacionada à obesidade aumentou dez vezes nos últimos anos. A obesidade também mostrou ser um fator de risco para nefrolitíase, e para uma série de tumores malignos, incluindo câncer renal. Este ano, o Dia Mundial do Rim promove orientações sobre as consequências prejudiciais da obesidade e sua associação com a doença renal, defendendo estilos de vida saudáveis e políticas de saúde que tornam comportamentos preventivos uma opção acessível.