Compromised Diet Quality is Associated with Decreased Renal Function in Children with Chronic Kidney Disease

Does the Nutritional Intake and Diet Quality of Children With Chronic Kidney Disease Differ From Healthy Controls? A Comprehensive Evaluation

OBJECTIVE

Children with chronic kidney disease (CKD) experience many obstacles to achieving optimal dietary intake. Dietary intake patterns remain unexplored or poorly described. This study compares nutritional intake and diet quality of Australian children with CKD to controls.

METHODS

A food frequency questionnaire captured intake data and was compared to controls. Nutritional intake was determined using individualized nutrient reference values, and diet quality described using the Australian Guide to Healthy Eating and the Australian Child and Adolescent Recommended Food Score.

RESULTS

Children with CKD (n = 36) and controls (n = 82) were studied. Children with CKD had lower weight and height z scores, but higher body mass index (P < .0001 for all parameters). Children with CKD had adequate energy intake, and excessive protein and sodium intake (336% and 569%). They were significantly less likely to meet requirements for vitamin A (P < .001), thiamine (P = .006), folate (P = .01), vitamin C (P = .008), calcium (P < .0001), iron (P = .01), magnesium (P = .0009), and potassium (P = .002). No child met recommended vegetable intake; however, less than half of children with CKD met fruit (44%), grains (31%), and dairy serves (31%). They were also less likely to meet recommended fruit and dairy serves (P = .04 and P = .01, respectively). Non-core foods provided 36% of energy, and although comparable to controls, was contributed more by takeaway foods (P = .01).

CONCLUSION

Children with CKD have reduced nutritional intake of key nutrients and consume more takeaways than controls. Attention to increasing core foods, limiting sodium intake, and managing restrictions while promoting nutrient density appears necessary.

Assessment and management of vitamin status in children with CKD stages 2-5, on dialysis and post-transplantation: clinical practice points from the Pediatric Renal Nutrition Taskforce

Children with chronic kidney disease (CKD) are at risk for vitamin deficiency or excess. Vitamin status can be affected by diet, supplements, kidney function, medications, and dialysis. Little is known about vitamin requirements in CKD, leading to practice variation.The Pediatric Renal Nutrition Taskforce (PRNT), an international team of pediatric kidney dietitians and pediatric nephrologists, was established to develop evidence-based clinical practice points (CPPs) to address challenges and to serve as a resource for nutritional care. Questions were formulated using PICO (Patient, Intervention, Comparator, Outcomes), and literature searches undertaken to explore clinical practice from assessment to management of vitamin status in children with CKD stages 2-5, on dialysis and post-transplantation (CKD2-5D&T). The CPPs were developed and finalized using a Delphi consensus approach. We present six CPPs for vitamin management for children with CKD2-5D&T. We address assessment, intervention, and monitoring. We recommend avoiding supplementation of vitamin A and suggest water-soluble vitamin supplementation for those on dialysis. In the absence of evidence, a consistent structured approach to vitamin management that considers assessment and monitoring from dietary, physical, and biochemical viewpoints is needed. Careful consideration of the impact of accumulation, losses, comorbidities, and medications needs to be explored for the individual child and vitamin before supplementation can be considered. When supplementing, care needs to be taken not to over-prescribe. Research recommendations are suggested.

Assessment of Dietary Phosphorus Intake and Implementation of Parental Phosphate Education in Pediatric Chronic Kidney Disease

Introduction

Management of dietary phosphorus intake is a challenge in children with chronic kidney disease and is governed by regional food sources and culinary practices. The aim of this study was to evaluate dietary intake of phosphorus in these children and assess the utility of parental phosphate education for control of hyperphosphatemia.

Methods

This prospective study included children aged 2-18 years with CKD stages 2-5D. Phosphorus intake was assessed by 24-hour dietary recall, analyzed using food processor software, and interpreted based on dietary reference intake (DRI) and suggested dietary intake (SDI). Parents of those with hyperphosphatemia were subjected to a structured phosphate education, and serum phosphate was monitored every 2 months for 6 months.

Results

Seventy children were recruited (mean age 9.4 ± 3.4 years, CKD5/5D: 51% (n = 36)) with median duration of CKD being 3.8 (IQR2,6) years. In the overall cohort, 50% (35/70) had phosphorus intake exceeding DRI with no significant difference between groups [CKD 5/5D,52.7% (n = 19) vs CKD2-4 47% (n = 16), P = 0.63]. Mean daily phosphorus intake was comparable between children with and without hyperphosphatemia [908 ± 279 mg vs 814 ± 302 mg, P = 0.1]. Based on DRI, 44% of children with normal serum phosphate and 58% with hyperphosphatemia had increased dietary intake of phosphorus (P = 0.15). Based on SDI, 26% with normal serum phosphate and 94% with hyperphosphatemia had increased dietary phosphorus intake (P < 0.001). Hyperphosphatemia was observed in 51% (CKD 2-4); 33% CKD5-5D 66%, P = 0.6). Among 29 children completing 6 months of follow up, there was a significant reduction in mean serum phosphate levels (P = 0.001) which was independent of age, stage of CKD or intake of phosphate binders. At end of the study, hyperphosphatemia persisted in 34%.

Conclusion

Compared to DRI, dietary assessment of phosphorus intake based on SDI was significantly associated with hyperphosphatemia in children with CKD 2-5D. In the majority, repeated parental structured phosphate education over 6 months was useful in managing hyperphosphatemia.

Scoping review of the dietary intake of children with chronic kidney disease

BACKGROUND

Adequate nutrition is integral to optimal health outcomes for children with chronic kidney disease. However, no studies to date have summarised the existing knowledge base on the dietary intake of this patient group.

OBJECTIVE

Analyse and summarise evidence regarding the dietary intake of children with chronic kidney disease and identify areas that require further research or clarification.

METHODS

A scoping review of English language articles using four bibliographic databases and a predefined search term strategy. Weighted mean intake for each nutrient was calculated.

RESULTS

Eighteen studies were identified (1407 children and 118 healthy controls). Data on socioeconomic status, underreporting of intake and binder use was sparse. Most studies collected dietary information using food records or 24-h recalls. Nutrient data was missing for many subgroups especially transplant and dialysis patients. Protein intake was excessive in all groups where data was reported and varied from 125.7 ± 33% of the recommended dietary allowance in the severe disease group to 391.3 ± 383% in the group with mild kidney disease. Fibre, calcium, iron and vitamin C intake was inadequate for all groups. For children undertaking dialysis, none met the recommended dietary allowance for vitamins C, B1, B2, B3, B5 and B6. Sodium intake was excessive in all groups (> 220% of the recommended dietary allowance). Limited data suggests diet quality is poor, particularly fruit and vegetable intake.

CONCLUSIONS

This review has identified important subgroups of children with kidney disease where nutrient intake is suboptimal or not well described. Future studies should be conducted to describe intake in these groups. A higher-resolution version of the graphical abstract is available as Supplementary information.

Assessment of nutritional status in children with kidney diseases-clinical practice recommendations from the Pediatric Renal Nutrition Taskforce

In children with kidney diseases, an assessment of the child's growth and nutritional status is important to guide the dietary prescription. No single metric can comprehensively describe the nutrition status; therefore, a series of indices and tools are required for evaluation. The Pediatric Renal Nutrition Taskforce (PRNT) is an international team of pediatric renal dietitians and pediatric nephrologists who develop clinical practice recommendations (CPRs) for the nutritional management of children with kidney diseases. Herein, we present CPRs for nutritional assessment, including measurement of anthropometric and biochemical parameters and evaluation of dietary intake. The statements have been graded using the American Academy of Pediatrics grading matrix. Statements with a low grade or those that are opinion-based must be carefully considered and adapted to individual patient needs based on the clinical judgment of the treating physician and dietitian. Audit and research recommendations are provided. The CPRs will be periodically audited and updated by the PRNT.

Dietary calcium intake does not meet the nutritional requirements of children with chronic kidney disease and on dialysis

BACKGROUND

Adequate calcium (Ca) intake is required for bone mineralization in children. We assessed Ca intake from diet and medications in children with CKD stages 4-5 and on dialysis (CKD4-5D) and age-matched controls, comparing with the UK Reference Nutrient Intake (RNI) and international recommendations.

METHODS

Three-day prospective diet diaries were recorded in 23 children with CKD4-5, 23 with CKD5D, and 27 controls. Doses of phosphate (P) binders and Ca supplements were recorded.

RESULTS

Median dietary Ca intake in CKD4-5D was 480 (interquartile range (IQR) 300-621) vs 724 (IQR 575-852) mg/day in controls (p = 0.00002), providing 81% vs 108% RNI (p = 0.002). Seventy-six percent of patients received < 100% RNI. In CKD4-5D, 40% dietary Ca was provided from dairy foods vs 56% in controls. Eighty percent of CKD4-5D children were prescribed Ca-based P-binders, 15% Ca supplements, and 9% both medications, increasing median daily Ca intake to 1145 (IQR 665-1649) mg/day; 177% RNI. Considering the total daily Ca intake from diet and medications, 15% received < 100% RNI, 44% 100-200% RNI, and 41% > 200% RNI. Three children (6%) exceeded the National Kidney Foundation Kidney Disease Outcomes Quality Initiative (KDOQI) upper limit of 2500 mg/day. None with a total Ca intake < RNI was hypocalcemic, and only one having > 2 × RNI was hypercalcemic.

CONCLUSIONS

Seventy-six percent of children with CKD4-5D had a dietary Ca intake < 100% RNI. Restriction of dairy foods as part of a P-controlled diet limits Ca intake. Additional Ca from medications is required to meet the KDOQI guideline of 100-200% normal recommended Ca intake. Graphical abstract.

Dietary sources of energy and nutrient intake among children and adolescents with chronic kidney disease

BACKGROUND

Our purpose was to identify the main food contributors to energy and nutrient intake in children with chronic kidney disease (CKD).

METHODS

In this cross-sectional study of dietary intake assessed using Food Frequency Questionnaires (FFQ) in the Chronic Kidney Disease in Children (CKiD) cohort study, we estimated energy and nutrient intake and identified the primary contributing foods within this population.

RESULTS

Completed FFQs were available for 658 children. Of those, 69.9% were boys, median age 12 (interquartile range (IQR) 8-15 years). The average daily energy intake was 1968 kcal (IQR 1523-2574 kcal). Milk was the largest contributor to total energy, protein, potassium, and phosphorus intake. Fast foods were the largest contributors to fat and sodium intake, the second largest contributors to energy intake, and the third largest contributors to potassium and phosphorus intake. Fruit contributed 12.0%, 8.7%, and 6.7% to potassium intake for children aged 2-5, 6-13, and 14-18 years old, respectively.

CONCLUSIONS

Children with CKD consumed more sodium, protein, and calories but less potassium than recommended by the National Kidney Foundation (NKF) guidelines for pediatric CKD. Energy, protein, and sodium intake is heavily driven by consumption of milk and fast foods. Limiting contribution of fast foods in patients with good appetite may be particularly important for maintaining recommended energy and sodium intake, as overconsumption can increase the risk of obesity and cardiovascular complications in that population.

Dietary Energy Density, Renal Function, and Progression of Chronic Kidney Disease

Background. There is evidence of the association between dietary energy density and chronic diseases. However, no report exists regarding the relation between DED and chronic kidney disease (CKD). Objective. To examine the association between dietary energy density (DED), renal function, and progression of chronic kidney disease (CKD). Design. Cross-sectional. Setting. Three nephrology clinics. Subjects. Two hundred twenty-one subjects with diagnosed CKD. Main Outcome Measure. Dietary intake of patients was assessed by a validated food frequency questionnaire. DED (in kcal/g) was calculated with the use of energy content and weight of solid foods and energy yielding beverages. Renal function was measured by blood urea nitrogen (BUN), serum creatinine (Cr), and estimated glomerular filtration rate (eGFR). Results. Patients in the first tertile of DED consumed more amounts of carbohydrate, dietary fiber, potassium, phosphorus, zinc, magnesium, calcium, folate, vitamin C, and vitamin B2. After adjusting for confounders, we could not find any significant trend for BUN and Cr across tertiles of DED. In multivariate model, an increased risk of being in the higher stage of CKD was found among those in the last tertile of DED (OR: 3.15; 95% CI: 1.30, 7.63; P = 0.01). Conclusion. We observed that lower DED was associated with better nutrient intake and lower risk of CKD progression.