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 (ß = - 0.98; 95% CI - 1.78, - 0.18, p = 0.02). Errors of omission were significantly higher (worse) in those with persistent anemia (ß = 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 (ß = - 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 (ß = - 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.

Low variability of plant protein intake in the CKiD cohort does not demonstrate changes in estimated GFR nor electrolyte balance.

BACKGROUND: Vegetable or plant-based sources of protein may confer health benefits in children with progressive kidney disease. Our aims were to understand the effect of the proportion of vegetable protein intake on changes in estimated GFR and to understand the effect of the proportion of vegetable protein intake on serum levels of bicarbonate, phosphorus, and potassium. METHODS: Children with baseline eGFR between 30 and 90 mL/min/1.73 m2 were recruited from 59 centers across North America as part of the chronic kidney disease in children (CKiD) study. The percentage of dietary vegetable protein (VP%) was gathered from annual Food Frequency Questionnaires. We performed longitudinal linear mixed models to determine the effect of VP% on eGFR and longitudinal logistic mixed models to determine the effect of VP% on electrolyte balance (potassium, phosphorus, bicarbonate). RESULTS: Two thousand visits from 631 subjects. Across all dichotomized groups of children (sex, African American race, Hispanic ethnicity, glomerular etiology of CKD, hypertension, anemia, hyperkalemia, hyperphosphatemia, acidosis, BMI < 95th percentile), the median VP% was 32-35%. The longitudinal mixed model analysis did not show any effect of VP% on eGFR electrolyte (bicarbonate, phosphorus, and potassium) abnormalities (p > 0.1). CONCLUSIONS: A diverse cohort of children with CKD has a narrow and homogeneous intake of vegetable protein. Due to the low variability of plant-based protein in the cohort, there were no associations between the percentage of plant protein intake and changes in eGFR nor electrolyte balance. A higher resolution version of the Graphical abstract is available as Supplementary information.