Longitudinal outcomes of body mass index in overweight and obese children with chronic kidney disease

Role of Nutrients in Pediatric Non-Dialysis Chronic Kidney Disease: From Pathogenesis to Correct Supplementation

Nutrition management is fundamental for children with chronic kidney disease (CKD). Fluid balance and low-protein and low-sodium diets are the more stressed fields from a nutritional point of view. At the same time, the role of micronutrients is often underestimated. Starting from the causes that could lead to potential micronutrient deficiencies in these patients, this review considers all micronutrients that could be administered in CKD to improve the prognosis of this disease.

Associations of body mass index (BMI) and BMI change with progression of chronic kidney disease in children

BACKGROUND

Obesity is prevalent among children with chronic kidney disease (CKD) and is associated with cardiovascular disease and reduced quality of life. Its relationship with pediatric CKD progression has not been described.

METHODS

We evaluated relationships between both body mass index (BMI) category (normal, overweight, obese) and BMI z-score (BMIz) change on CKD progression among participants of the Chronic Kidney Disease in Children study. Kaplan-Meier survival curves and multivariable parametric failure time models depict the association of baseline BMI category on time to kidney replacement therapy (KRT). Additionally, the annualized percentage change in estimated glomerular filtration rate (eGFR) was modeled against concurrent change in BMIz using multivariable linear regression with generalized estimating equations which allowed for quantification of the effect of BMIz change on annualized eGFR change.

RESULTS

Participants had median age of 10.9 years [IQR: 6.5, 14.6], median eGFR of 50 ml/1.73 m2 [IQR: 37, 64] and 63% were male. 160 (27%) of 600 children with non-glomerular and 77 (31%) of 247 children with glomerular CKD progressed to KRT over a median of 5 years [IQR: 2, 8]. Times to KRT were not significantly associated with baseline BMI category. Children with non-glomerular CKD who were obese experienced significant improvement in eGFR (+ 0.62%; 95% CI: + 0.17%, + 1.08%) for every 0.1 standard deviation concurrent decrease in BMI. In participants with glomerular CKD who were obese, BMIz change was not significantly associated with annualized eGFR change.

CONCLUSION

Obesity may represent a target of intervention to improve kidney function in children with non-glomerular CKD. 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.

An ethical analysis of obesity as a contraindication of pediatric kidney transplant candidacy

The inclusion of body mass index (BMI) as a criterion for determining kidney transplant candidacy in children raises clinical and ethical challenges. Childhood obesity is on the rise and common among children with kidney failure. In addition, obesity is reported as an independent risk factor for the development of CKD and kidney failure. Resultantly, more children with obesity are anticipated to need kidney transplants. Most transplant centers around the world use high BMI as a relative or absolute contraindication for kidney transplant. However, use of obesity as a relative or absolute contraindication for pediatric kidney transplant is controversial. Empirical data demonstrating poorer outcomes following kidney transplant in obese pediatric patients are limited. In addition, pediatric obesity is distributed inequitably among groups. Unlike adults, most children lack independent agency to choose their food sources and exercise opportunities; they are dependent on their families for these choices. In this paper, we define childhood obesity and review (1) the association and impact of obesity on kidney disease and kidney transplant, (2) existing adult guidelines and rationale for using high BMI as a criterion for kidney transplant, (3) the prevalence of childhood obesity among children with kidney failure, and (4) the existing literature on obesity and pediatric kidney transplant outcomes. We then discuss ethical considerations related to the use of obesity as a criterion for kidney transplant.

Managing the Nutritional Requirements of the Pediatric End-Stage Kidney Disease Graduate

The pediatric patient with end-stage kidney disease who transitions to the adult dialysis unit or nephrology center requires a unique nutritional focus. Clinicians in the adult center may be faced with complex issues that have often been part of the patient's journey since early childhood. The causes of kidney disease in children are often quite different than those which affect the adult population and may require different nutritional priorities. Abnormal growth including severe short stature, underweight, overweight or obesity, and poor musculature may affect the long-term health and psychosocial well-being of these patients. Nutritional assessment of these patients should include a focus on past growth and anthropometric data, dietary information, including appetite, quality of diet, and assessment of biochemical data through a pediatric lens. This review discusses the unique factors that must be considered when transitioning pediatric patients and notes major recommendations from a compilation of pediatric guideline statements.