Cardiovascular disease risk factors and lifestyle modification strategies after pediatric kidney transplantation: what are we dealing with, and what can we target?

Kidney transplantation in pediatric patients can lead to partial improvement of some of the cardiometabolic parameters that increase the risk for cardiovascular disease (CVD) in patients with chronic kidney disease. However, even after restoration of kidney function, transplant recipients remain at risk for CVD due to the continual presence of traditional and non-traditional risk factors, including the side effects of immunosuppression and chronic inflammation. This educational review describes the prevalence of CVD risk factors in pediatric kidney transplant recipients and presents available evidence for therapeutic lifestyle changes and other non-pharmacologic strategies that can be used to improve traditional and modifiable CVD risk factors. Although trial-grade evidence for interventions that improve CVD in pediatric kidney transplant recipients is limited, potential strategies include lowering dietary sodium and saturated fat intake and increasing physical activity levels. Intensive follow-up may help patients achieve guideline-recommended goals for reducing their overall CVD risk.

Effect of pre and post-transplant body mass index on pediatric kidney transplant outcomes

Introduction

Kidney transplantation (KT) has been established as an efficient treatment of end stage renal disease (ESRD) with the advantage of allowing the patient to live a nearly healthy life. We aimed to determine whether pre-transplant body mass index (BMI) affects renal allograft function and survival in pediatric KT recipients.

Methods

cross sectional cohort study included 50 post KT recipients (more than 3 years) with an age range of 10 to 15 years, regularly following at the Kidney Transplantation Outpatient Clinic, Cairo University Children’s Hospital, were subjected to a detailed history and physical examination, laboratory investigation in the form of fasting blood glucose (FBG),oral glucose tolerance test (OGTT), lipid profile, hemoglobin A1c (HbA1c) and microalbuminuria.

Results

Pre- post- kidney transplant BMI has significant positive correlation with graft rejection episodes, HbA1c, FBG, BMI post-KT, total cholesterol, triglycerides, and low-density lipoprotein (p < 0.01). There was a statistically significant negative correlation between the mean difference of BMI (post – pre) and graft survival in years (p = 0.036). Obese patients displayed lower survival compared with non-obese subjects at 5 years, but this was statistically not significant (p-value = 0.165).

Conclusion

obesity is an independent risk factor for graft loss and patient death in kidney transplantation. Careful patient selection with pre-transplantation weight reduction is mandatory to reduce the rate of early post-transplantation complications and to improve long-term outcomes.

Acute rejection and growth outcomes in paediatric kidney allograft recipients treated with a corticosteroid minimisation immunosuppressive protocol

BACKGROUND

Corticosteroid minimisation immunosuppressive protocols (CMP) for children are an approach to safely reduce unwanted medication side effects associated with long-term exposure following kidney transplantation. Here, we provide data regarding the incidence of acute rejection and growth over an extended follow-up in children receiving the CMP used in our centre.

METHODS

We retrospectively analysed all children treated with a CMP who received a kidney transplant and had follow-up care in our centre between 2009 and 2019. Data were compared to 5 control groups from recent studies.

RESULTS

Ninety-nine kidney allograft recipients were included in the study (mean follow-up 4.4 years). There was no difference in the cumulative frequency of acute rejection in CMP-treated graft recipients compared to controls. Graft function at latest follow-up was significantly lower in graft recipients experiencing acute rejection compared to those without acute rejection (53.7 mL/min/1.73 m² vs. 66.8 mL/min/1.73 m², p = 0.021). Children experiencing >1 acute rejection episode had a greatly elevated risk of graft failure (p = 0.0009, OR 68.25). At latest follow-up, 64/90 (71.1%) graft recipients had a normal height, and younger graft recipients demonstrated greater catch up growth than older children. CMP-treated graft recipients showed a reduced rate of height deficit (28.9% vs. 55.1%, p = 0.0025), less obesity (12.2% vs. 23.9%, p = 0.031), and reduced rates of hypertension (35.4% vs. 68.2%, p< 0.0001).

CONCLUSIONS

Children treated with a CMP show greater height attainment, lower frequency of obesity, and reduced rates of hypertension, without an increased risk of acute rejection. Graphical abstract.

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

BACKGROUND

Longitudinal changes in body mass index (BMI) among overweight and obese children with chronic kidney disease (CKD) are not well characterized. We studied longitudinal trajectories and correlates of these trajectories, as results may identify opportunities to optimize health outcomes.

METHODS

Longitudinal changes in age-sex-specific BMI z-scores over 1851 person-years of follow-up were assessed in 524 participants of the Chronic Kidney Disease in Children Study. A total of 353 participants were categorized as normal (BMI > 5th to < 85th percentile), 56 overweight (BMI ≥ 85th to 95th percentile) and 115 obese (BMI ≥ 95th percentile) based on the average of three BMI measurements during the first year of follow-up. Studied covariates included age, sex, race, CKD etiology, corticosteroid usage, household income, and maternal education.

RESULTS

In unadjusted analysis, BMI z-scores decreased over time in elevated BMI groups (overweight: mean = - 0.06 standard deviations (SD) per year, 95% CI: - 0.11, - 0.01; obese: mean = - 0.04 SD per year, 95% CI: - 0.07, - 0.01). Among obese children, only age was associated with change in BMI z-score; children < 6 years had a mean decrease of 0.19 SD during follow-up (95% CI: - 0.30, - 0.09). Socioeconomic factors were not associated with change in BMI.

CONCLUSION

Overweight and obese children with CKD demonstrated a significant annual decline in BMI, though the absolute change was modest. Among obese children, only age < 6 years was associated with significant decline in BMI. Persistence of elevated BMI in older children and adolescents with CKD underscores the need for early prevention and effective intervention.

Can childhood obesity influence later chronic kidney disease?

Childhood overweight and obesity affects more and more children. Whilst associations of childhood overweight with later outcomes such as hypertension, diabetes and cardiovascular disease have been well documented, less is known about the association of childhood overweight and obesity with kidney disease. We review the existing evidence for the association of childhood obesity with markers of childhood and adult kidney disease. Whilst there is some evidence for an association, studies have not been able to distinguish between childhood being a sensitive time to develop later kidney problems, or whether observed associations of childhood obesity with poor outcomes are driven by greater lifelong exposure to obesity.

Obesity in pediatric kidney transplant recipients and the risks of acute rejection, graft loss and death

BACKGROUND

Obesity is prevalent in children with chronic kidney disease (CKD), but the health consequences of this combination of comorbidities are uncertain. The aim of this study was to evaluate the impact of obesity on the outcomes of children following kidney transplantation.

METHODS

Using data from the ANZDATA Registry (1994-2013), we assessed the association between age-appropriate body mass index (BMI) at the time of transplantation and the subsequent development of acute rejection (within the first 6 months), graft loss and death using adjusted Cox proportional hazards models.

RESULTS

Included in our analysis were 750 children ranging in age from 2 to 18 (median age 12) years with a total of 6597 person-years of follow-up (median follow-up 8.4 years). Overall, at transplantation 129 (17.2%) children were classified as being overweight and 61 (8.1%) as being obese. Of the 750 children, 102 (16.2%) experienced acute rejection within the first 6 months of transplantation, 235 (31.3%) lost their allograft and 53 (7.1%) died. Compared to children with normal BMI, the adjusted hazard ratios (HR) for graft loss in children who were underweight, overweight or diagnosed as obese were 1.05 [95% confidence interval (CI) 0.70-1.60], 1.03 (95% CI 0.71-1.49) and 1.61 (95% CI 1.05-2.47), respectively. There was no statistically significant association between BMI and acute rejection [underweight: HR 1.07, 95% CI 0.54-2.09; overweight: HR 1.42, 95% CI 0.86-2.34; obese: HR 1.83, 95% CI 0.95-3.51) or patient survival (underweight: HR 1.18, 95% CI 0.54-2.58, overweight: HR 0.85, 95% CI 0.38-1.92; obese: HR 0.80, 95% CI 0.25-2.61).

CONCLUSIONS

Over 10 years of follow-up, pediatric transplant recipients diagnosed with obesity have a substantially increased risk of allograft failure but not acute rejection of the graft or death.

Pediatric kidney transplantation

Since first performed in 1954, kidney transplantation has evolved as the preferred long-term treatment of children with end stage renal disease (ESRD). The etiology of chronic kidney disease (CKD) and ESRD in children is broad and can be quite complicated, necessitating a multidisciplinary team to adequately care for these patients and their myriad needs. Precise surgical techniques and modern protocols for immunosuppression provide excellent long-term patient and graft survival. This article reviews the many etiologies of renal failure in the pediatric population focusing on those most commonly leading to the need for kidney transplantation. The processes of evaluation, kidney transplantation, short-term and long-term complications, as well as long-term outcomes are also reviewed.

Single-center assessment of nutritional counseling in preventing excessive weight gain in pediatric renal transplants recipients

Post-transplantation obesity is a common complication that is associated with a higher risk for decreased allograft function and hypertension. However, the role of diet intervention on reducing post-transplantation obesity is relatively unknown. We investigated the clinical relevance of dietary counseling on the prevalence of overweight/obesity during the first two yr following renal transplantation. The computerized patient records of 42 recipients (31 males) aged 6.3 ± 4.8 yr at transplantation were reviewed. All patients systematically underwent yearly dietary assessment/counseling (motivational interviewing technique) and measurement of renal function and ABPM. At transplantation, 14.2% of patients were overweight/obese, which increased to 42.8% by two yr post-transplantation (p = 0.004). The majority of patients experienced a significant increase in BMI SDS during the first six months post-transplantation that remained sustained throughout the duration of the follow-up period (p = 0.001). By two yr post-transplantation, there were no observable differences between patients classified as having normal BMI or being overweight/obese with regard to renal function and controlled hypertension. The application of yearly tailored dietary assessment/counseling had a poor effect on preventing post-transplantation weight gain, suggesting the need for more comprehensive interventions to reduce post-transplant obesity.

Paediatric obesity and renal transplantation: current challenges and solutions

The increased incidence of obesity in the paediatric population poses significant challenges to renal transplantation. Whilst the body mass index appears to be widely used as a measure of obesity in adults, there are no standardised definitions in the paediatric population, making comparative analyses difficult. In the paediatric transplant population, obesity is associated with an increased incidence of surgical complications, diabetes, hyperlipidaemia and cardiovascular morbidity, leading to diminished graft function and impacting patient and graft survival. Management of obesity in renal transplantation requires multiple interventions starting with life-style and behavioural modification combined with medical and possibly surgical therapies, representing a unique challenge in the childhood setting. In this review we discuss the current challenges of obesity and potential solutions in the setting of paediatric transplantation.

Practical Nutrition Management of Children with Chronic Kidney Disease

Chronic kidney disease (CKD) introduces a unique set of nutritional challenges for the growing and developing child. This article addresses initial evaluation and ongoing assessment of a child with CKD. It aims to provide an overview of nutritional challenges unique to a pediatric patient with CKD and practical management guidelines. Caloric assessment in children with CKD is critical as many factors contribute to poor caloric intake. Tube feeding is a practical option to provide the required calories and fluid in children who have difficulty with adequate oral intake. Protein intake should not be limited and should be further adjusted for protein loss with dialysis. Supplementation or restriction of sodium is patient specific. Urine output, fluid status, and modality of dialysis are factors that influence sodium balance. Hyperkalemia poses a significant cardiac risk, and potassium is closely monitored. In addition to a low potassium diet, potassium binders may be prescribed to reduce potassium load from oral intake. Phosphorus and calcium play a significant role in cardiovascular and bone health. Phosphorus binders have helped children and families manage phosphorus levels in conjunction with a phosphorus-restricted diet. Nutritional management of children with CKD is a challenge that requires continuous reassessment and readjustment as the child ages, CKD progresses, and urine output decreases.

Decreased arterial elasticity in children with nondialysis chronic kidney disease is related to blood pressure and not to glomerular filtration rate

We compared large artery mechanical properties in children with nondialysis stages of chronic kidney disease with those in children with normal renal function, examining the potential effect of blood pressure (BP) components and level of renal dysfunction. Common carotid artery mechanical properties, carotid-femoral pulse wave velocity, and carotid and peripheral BP were measured in children (n=226) with nondialysis chronic kidney disease (n=188; 11.9±3.7 years; 26%, 25%, 30%, 16%, and 3% in stages 1, 2, 3, 4 and 5, respectively) and healthy controls (n=38; 11.5±3.3 years). In children with nondialysis chronic kidney disease when compared with healthy controls, at similar levels of peripheral and carotid BP, carotid artery diastolic diameter and wall thickness were similar. In those with suboptimal BP (≥75th percentile), indices of arterial elasticity indicated greater stiffness than in healthy normotensive controls (distensibility: 92±31 versus 114±33 kPa(-1)×10(-3), P=0.03; compliance: 2.1±0.7 versus 2.6±0.7 m(2) kPa(-1)×10(-6), P=0.02; Young elastic modulus: 0.151±0.068 versus 0.109±0.049 kPa×10(3), P=0.02; and wall stress: 83.6±23.5 versus 68.7±14.9 kPa, P=0.02). In all children, mechanical properties were independently related to carotid and peripheral BP components but not to estimated glomerular filtration rate. In children with nondialysis chronic kidney disease, changes in elastic properties of the carotid artery are primarily related to BP and not to glomerular renal function.