Energy and nutrient intake of patients with mild-to-moderate chronic renal failure compared with healthy children: an Italian multicentre study

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.

Impact of the COVID-19 pandemic on body mass index in children and adolescents after kidney transplantation

BACKGROUND

The coronavirus SARS-CoV-2 disease (COVID-19) pandemic affected lifestyles and resulted in significant weight gain in the general population. Its impact on children after kidney transplantation (KTx) is unknown.

METHODS

We retrospectively evaluated body mass index (BMI) z-scores during the COVID-19 pandemic in 132 pediatric KTx patients, followed-up at three German hospitals. Among those, serial blood pressure measurements were available for 104 patients. Lipid measurements were available from 74 patients. Patients were categorized according to gender and age group, i.e., children versus adolescents. Data were analyzed by a linear mixed model approach.

RESULTS

Before the COVID-19 pandemic, female adolescents presented with higher mean BMI z-scores compared to male adolescents (difference: - 1.05, 95% CI - 1.86 to - 0.24, p = 0.004). No other significant differences could be observed among the other groups. During the COVID-19 pandemic, the mean BMI z-score increased in adolescents (difference: male, 0.23, 95% CI 0.18 to 0.28; female 0.21, 95% CI 0.14 to 0.29, each p < 0.001), but not in children. The BMI z-score was associated with adolescent age, and with the combination of adolescent age, female gender, and the duration of the pandemic (each p < 0.05). During the COVID-19 pandemic, the mean systolic blood pressure z-score significantly increased in female adolescents (difference: 0.47, 95% CI 0.46 to 0.49).

CONCLUSIONS

During the COVID-19 pandemic, adolescents in particular showed a significant increase in their BMI z-score after KTx. Additionally, an increase in systolic blood pressure was associated with female adolescents. The findings suggest additional cardiovascular risks in this cohort. A higher resolution version of the Graphical abstract is available as Supplementary information.

Malnutrition Patterns in Children with Chronic Kidney Disease

Malnutrition is frequent in children with chronic kidney disease (CKD). Apart from undernutrition and protein energy wasting (PEW), overnutrition prevalence is rising, resulting in fat mass accumulation. Sedentary behavior and unbalanced diet are the most important causal factors. Both underweight and obesity are linked to adverse outcomes regarding renal function, cardiometabolic risk and mortality rate. Muscle wasting is the cornerstone finding of PEW, preceding fat loss and may lead to fatigue, musculoskeletal decline and frailty. In addition, clinical data emphasize the growing occurrence of muscle mass and strength deficits in patients with fat mass accumulation, attributed to CKD-related wasting processes, reduced physical activity and possibly to obesity-induced inflammatory diseases, leading to sarcopenic obesity. Moreover, children with CKD are susceptible to abdominal obesity, resulting from high body fat distribution into the visceral abdomen compartment. Both sarcopenic and abdominal obesity are associated with increased cardiometabolic risk. This review analyzes the pathogenetic mechanisms, current trends and outcomes of malnutrition patterns in pediatric CKD. Moreover, it underlines the importance of body composition assessment for the nutritional evaluation and summarizes the advantages and limitations of the currently available techniques. Furthermore, it highlights the benefits of growth hormone therapy and physical activity on malnutrition management.

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.

Energy and protein requirements for children with CKD stages 2-5 and on dialysis-clinical practice recommendations from the Pediatric Renal Nutrition Taskforce

Dietary management in pediatric chronic kidney disease (CKD) is an area fraught with uncertainties and wide variations in practice. Even in tertiary pediatric nephrology centers, expert dietetic input is often lacking. The Pediatric Renal Nutrition Taskforce (PRNT), an international team of pediatric renal dietitians and pediatric nephrologists, was established to develop clinical practice recommendations (CPRs) to address these challenges and to serve as a resource for nutritional care. We present CPRs for energy and protein requirements for children with CKD stages 2-5 and those on dialysis (CKD2-5D). We address energy requirements in the context of poor growth, obesity, and different levels of physical activity, together with the additional protein needs to compensate for dialysate losses. We describe how to achieve the dietary prescription for energy and protein using breastmilk, formulas, food, and dietary supplements, which can be incorporated into everyday practice. Statements with a low grade of evidence, or based on opinion, must be considered and adapted for the individual patient by the treating physician and dietitian according to their clinical judgment. Research recommendations have been suggested. The CPRs will be regularly 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.

Serum Trace Elements in Children with End-Stage Renal Disease

OBJECTIVES

Trace elements, which have a crucial role in metabolism and enzymatic pathways, are not routinely monitored in the blood of pediatric patients with chronic kidney disease. The present study was carried out to determine the serum levels of copper (Cu), zinc (Zn), selenium (Se), and lead (Pb) in children with ESRD who were currently receiving conservative management or were on long-term hemodialysis or continuous ambulatory peritoneal dialysis.

METHODS

This study involved 200 children who met the inclusion criteria. The children were divided into 4 groups: a hemodialysis group, a peritoneal dialysis group, a group of children with ESRD treated with conservative management, and a control group. Serum levels of Zn, Cu, Se, and Pb were evaluated using an atomic absorption spectrophotometer and compared between the groups.

RESULTS

There was no significant difference in the serum concentration of Cu among the 4 study groups. There was also no significant difference in the serum concentrations of Zn, Se, and Pb between healthy children and children with CKD treated with conservative management or between the hemodialysis and peritoneal dialysis groups. The levels of Zn and Se were significantly lower in the hemodialysis and peritoneal dialysis groups than in the healthy children or in children with CKD treated with conservative management. The level of Pb in the blood was significantly lower in healthy children and children with CKD treated with conservative management than in the hemodialysis or peritoneal dialysis groups.

CONCLUSIONS

The levels of trace elements were substantially different between the dialysis groups and healthy children and children with CKD treated with conservative management. These results highlighted the role of osmosis during dialysis, as dialysate impurities can cause a disturbance in the levels of trace elements and the role of the kidney, even with minimum residual function, in the homeostasis of trace elements.

Vitamin and trace element deficiencies in the pediatric dialysis patient

Pediatric dialysis patients are at risk of nutritional illness secondary to deficiencies in water-soluble vitamins and trace elements. Unlike 25-OH vitamin D, most other vitamins and trace elements are not routinely monitored in the blood and, consequently, the detection of any deficiency may not occur until significant complications develop. Causes of vitamin and trace element deficiency in patients on maintenance dialysis patient are multifactorial, ranging from diminished nutritional intake to altered metabolism as well as dialysate-driven losses of water-soluble vitamins and select trace elements. In this review we summarize the nutritional sources of key water-soluble vitamins and trace elements with a focus on the biological roles and clinical manifestations of their respective deficiency to augment awareness of potential nutritional illness in pediatric patients receiving maintenance dialysis. The limited pediatric data on the topic of clearance of water-soluble vitamins and trace elements by individual dialysis modality are reviewed, including a brief discussion on clearance of water-soluble vitamins and trace elements with continuous renal replacement therapy.

Nutrition in children with CRF and on dialysis

The objectives of this study are: (1) to understand the importance of nutrition in normal growth; (2) to review the methods of assessing nutritional status; (3) to review the dietary requirements of normal children throughout childhood, including protein, energy, vitamins and minerals; (4) to review recommendations for the nutritional requirements of children with chronic renal failure (CRF) and on dialysis; (5) to review reports of spontaneous nutritional intake in children with CRF and on dialysis; (6) to review the epidemiology of nutritional disturbances in renal disease, including height, weight and body composition; (7) to review the pathological mechanisms underlying poor appetite, abnormal metabolic rate and endocrine disturbances in renal disease; (8) to review the evidence for the benefit of dietetic input, dietary supplementation, nasogastric and gastrostomy feeds and intradialytic nutrition; (9) to review the effect of dialysis adequacy on nutrition; (10) to review the effect of nutrition on outcome.

Dietary intake and nutritional status of children and adolescents in Europe

The objective of this project was to collect and evaluate data on nutrient intake and status across Europe and to ascertain whether any trends could be identified. Surveys of dietary intake and status were collected from across Europe by literature search and personal contact with country experts. Surveys that satisfied a defined set of criteria – published, based on individual intakes, post-1987, adequate information provided to enable its quality to be assessed, small age bands, data for sexes separated above 12 years, sample size over 25 and subjects representative of the population – were selected for further analysis. In a small number of cases, where no other data for a country were available or where status data were given, exceptions were made. Seventy-nine surveys from 23 countries were included, and from them data on energy, protein, fats, carbohydrates, alcohol, vitamins, minerals and trace elements were collected and tabulated. Data on energy, protein, total fat and carbohydrate were given in a large number of surveys, but information was very limited for some micronutrients. No surveys gave information on fluid intake and insufficient gave data on food patterns to be of value to this project. A variety of collection methods were used, there was no consistency in the ages of children surveyed or the age cut-off points, but most surveys gave data for males and females separately at all ages. Just under half of the surveys were nationally representative and most of the remainder were regional. Only a small number of local surveys could be included. Apart from anthropometric measurements, status data were collected in only seven countries. Males had higher energy intakes than females, energy intake increased with age but levelled off in adolescent girls. Intakes of other nutrients generally related to energy intakes. Some north–south geographical trends were noted in fat and carbohydrate intakes, but these were not apparent for other nutrients. Some other trends between countries were noted, but there were also wide variations within countries. A number of validation studies have shown that misreporting is a major problem in dietary surveys of children and adolescents and so all the dietary data collected for this project should be interpreted and evaluated with caution In addition, dietary studies rely on food composition tables for the conversion of food intake data to estimated nutrient intakes and each country uses a different set of food composition data which differ in definitions, analytical methods, units and modes of expression. This can make comparisons between countries difficult and inaccurate. Methods of measuring food intake are not standardised across Europe and intake data are generally poor, so there are uncertainties over the true nutrient intakes of children and adolescents across Europe. There are insufficient data on status to be able to be able to draw any conclusions about the nutritional quality of the diets of European children and adolescents.

Optimising nutrition in chronic renal insufficiency--progression of disease

There is a lack of evidence to support the belief that dietary measures are beneficial in slowing the progression of chronic renal insufficiency (CRI). We prospectively monitored nutrient intakes and progression of CRI over a 2-year period in children aged 2-16 years with differing levels of severity of CRI, as part of their ongoing joint medical/dietetic care. Children were grouped following [5'Cr]-labelled EDTA glomerular filtration rate(GFR, ml/min per 1.73 m 2) estimations, into 'normal'kidney function [GFR >75, mean 106 (SD 19.5), n=58],providing baseline data only, mild (GFR 51-75, n=25),moderate (GFR 25-50, n =21), and severe (GFR <25, n=19) CRI. Children with CRI were followed for 2 years,with 51 completing the study (19 mild, 19 moderate, 13 severe CRI) and were excluded if they subsequently required dialysis. Regular medical and dietary advice was provided and yearly 3-day semi-quantitative dietary di-aries and baseline and 6-monthly measurements of blood pressure and urinary protein/creatinine ratio were obtained. Mean reductions in estimated GFR over 2 years were -9.4, -5.8, and -6.0 ml/min per 1.73 m2 for mild,moderate, and severe CRI, respectively. Mean systolic blood pressure standard deviation score (SDS) fell significantly in all groups by 0.7 SDS, whereas there was little change in proteinuria. From reported dietary intakes,median sodium intakes increased (+10 mmol/day) and protein intakes decreased (-0.4 g/kg per day). Median phosphate intakes did not change significantly, where as calcium intakes fell in all groups, with an overall median of -20% reference nutrient intake (RNI) (F=33.3,P<0.001). Of children with moderate CRI, 65% finished with calcium intakes below 80% RNI, and parathyroid hormone (PTH) concentrations significantly increased in this group (F=6.0, P=0.021). Higher phosphate and sodium intakes were associated with greater deterioration in estimated GFR in children with mild CRI (r2=0.30,P=0.02; r-=0.31, P=0.02, respectively). There was no such correlation for protein intake or PTH. This study emphasises the need for a joint medical and dietetic approach and indicates a number of interventions other than protein restriction, which could be commenced early in children with CRI in an attempt to delay progression.

[Children with chronic renal failure: evaluation of the nutritional status and management]

Since malnutrition is a well recognized problem in children with chronic renal failure, nutritional management of these children is essential. This review describes methods for nutritional assessment and suggests guidelines for providing maximal dietary support in children with chronic renal insufficiency. Optimal nutritional management includes an adequate caloric and protein intake, a restriction of phosphorus intake and an appropriate intake of electrolytes and vitamins.

Nutritional intake in children with renal insufficiency: a report of the growth failure in children with renal diseases study

OBJECTIVE

This study was designed to assess sequentially the nutrient intake in children with chronic renal insufficiency and its relationship to body size, the level of renal failure, and growth velocity.

METHODS

The nutrient intake from 401 4-day food records obtained from 120 children with renal insufficiency over a 6-month observation period was analyzed. The height and weight were measured at the beginning and end of the observation period. The glomerular filtration rate was estimated from the height and serum creatinine.

RESULTS

The mean caloric intake in these children was 80 +/- 23% (mean +/- SD) of the Recommended Dietary Allowance (RDA) for age. Fifty-six percent of the food records obtained from these children revealed a caloric intake that was less than 80% of the RDA. Caloric intake expressed as the %RDA for age decreased with increasing age. However, the mean caloric intake when factored by body weight was in the normal range. There was no correlation between caloric intake and height velocity. The mean protein intake in these children was 153 +/- 53% of the RDA. Further, 45% of the food records indicated a protein intake greater than 150% of the RDA. There was no relationship between the degree of renal insufficiency and caloric or protein intake. Calcium, vitamin, and zinc intakes were also low.

CONCLUSIONS

Children with chronic renal failure consume less calories than their age matched peers, but the majority of these children appear to ingest adequate amounts for their body mass. This reduction in caloric intake occurs early in renal insufficiency. They also ingest inadequate amounts of calcium, zinc, vitamin B6, and folate.

Nutritional status of children with moderate chronic renal failure

Nutritional status was evaluated in 15 children (11 males) with moderate chronic renal failure (CRF). Two 3-day prospective dietary records, anthropometric measures and biochemical determinations were performed 3 months apart. Energy, protein, carbohydrate, fat, polyunsaturated, monounsaturated and saturated fatty acid intakes, expressed as percentages of international recommendations, were 87 +/- 14, 223 +/- 42, 73 +/- 12, 110 +/- 27, 55 +/- 31, 129 +/- 51 and 111 +/- 26%, respectively. The relative distribution of calories was 15 +/- 2% from proteins, 48 +/- 5% from carbohydrates and 37 +/- 5% from lipids. Anthropometric indices, expressed as standard deviation score, were: weight -0.50 +/- 0.8, height -0.94 +/- 1.3, growth velocity -0.61 +/- 1.8, triceps skinfold thickness -0.30 +/- 0.6, subscapular skinfold thickness -0.19 +/- 0.8, mid-arm muscle circumference 0.38 +/- 0.3 and body mass index -0.22 +/- 1.0. Serum concentrations of albumin, total protein, transferrin, IgG, IgA, IgM, C3 and C4 and blood lymphocyte counts were within normal limits. The mean serum insulin-like growth factor-I concentration, expressed as standard deviation score, as 0.74 +/- 1.5. No anthropometric or biochemical signs of malnutrition were found in children with moderate CRF. However, their dietary intake of calories and carbohydrates was low and the protein and saturated fatty acid intake excessively high.