Arterial changes in paediatric haemodialysis patients undergoing renal transplantation

Fibroblast growth factor 23: translating analytical improvement into clinical effectiveness for tertiary prevention in chronic kidney disease

OBJECTIVES

Fibroblast growth factor 23 (FGF23) plays a key role in the pathophysiology of chronic kidney disease (CKD) and of the associated cardiovascular diseases, ranking on the crossroads of several evolving areas with a relevant impact on the health-care system (ageing, treatment of CKD and prevention from cardiovascular and renal events). In this review, we will critically appraise the overall issues concerning the clinical usefulness of FGF23 determination in CKD, focusing on the analytical performances of the methods, aiming to assess whether and how the clinical introduction of FGF23 may promote cost-effective health care policies in these patients.

CONTENT

Our comprehensive critical appraisal of the literature revealed that we are currently unable to establish the clinical usefulness of FGF23 measured by ELISA in CKD, as stability issues and suboptimal analytical performances are the major responsible for the release of misleading results. The meta-analytical approach has failed to report unambiguous evidence in face of the wide heterogeneity of the results from single studies.

SUMMARY AND OUTLOOK

Our review has largely demonstrated that the clinical usefulness depends on a thorough analytical validation of the assay. The recent introduction of chemiluminescent intact-FGF23 (iFGF23) assays licensed for clinical use, after passing a robust analytical validation, has allowed the actual assessment of preliminary risk thresholds for cardiovascular and renal events and is promising to capture the iFGF23 clinically relevant changes as a result of a therapeutic modulation. In this perspective, the analytical optimization of FGF23 determination may allow a marriage between physiology and epidemiology and a merging towards clinical outcomes.

Dilatation of the aorta in children with advanced chronic kidney disease

BACKGROUND

The peculiarity of the cardiovascular risk profile with increased arterial vulnerability is well known in adults with chronic kidney disease (CKD). It is explained by an increased incidence of traditional cardiovascular risk factors together with other comorbidities related to the uremic condition and cardiorenal syndrome (CRS). The present study aimed to determine the cardiovascular impact of the uremic condition in a pediatric population with advanced CKD.

METHODS

From 2016 to 2018, 39 consecutive patients with advanced CKD who underwent echocardiographic evaluation were included. All echocardiographic examinations were performed by the same operator (FE). Demographic, clinical, biological, and echocardiographic data were collected.

RESULTS

The mean age at echocardiographic exam was 9.7 ± 4.6 years. Twenty-four (61.5%) patients were on hemodialysis; 17 (43.6%) patients were in a peritoneal dialysis program of whom 11 switched at a later stage to hemodialysis. Eight (20.5%) patients had an arteriovenous fistula (AVF). Hypertension was present in 30 (76.9%) patients while left ventricular hypertrophy (LVH) was described in 13 (33.3%) patients. Dilatation of the ascending aorta (Z-score > 2) was found in 15 (38.4%) patients and was statistically (in univariate analysis) related to gender, hypertension, the presence of an AVF, and the use of hemodialysis after peritoneal dialysis (p = 0.024, p = 0.016, p = 0.006, p = 0.009, respectively).

CONCLUSION

In addition to classical and predictable abnormalities related to CKD, we found a high prevalence of dilatation of the ascending aorta in children with advanced CKD. Hypertension, AVF, and hemodialysis were associated factors.

Cardiovascular disease in children with chronic kidney disease

More than a decade ago, cardiovascular disease (CVD) was recognized as a major cause of death in children with advanced CKD. This observation has sparked the publication of multiple studies assessing cardiovascular risk, mechanisms of disease, and early markers of CVD in this population. Similar to adults, children with CKD have an extremely high prevalence of traditional and uremia-related CVD risk factors. Early markers of cardiomyopathy, such as left ventricular hypertrophy and dysfunction, and early markers of atherosclerosis, such as increased carotid artery intima-media thickness, carotid arterial wall stiffness, and coronary artery calcification, are frequently present in these children, especially those on maintenance dialysis. As a population without preexisting symptomatic cardiac disease, children with CKD potentially receive significant benefit from aggressive attempts to prevent and treat CVD. Early CKD, before needing dialysis, is the optimal time to both identify modifiable risk factors and intervene in an effort to avert future CVD. Slowing the progression of CKD, avoiding long-term dialysis and, if possible, conducting preemptive transplantation may represent the best strategies to decrease the risk of premature cardiac disease and death in children with CKD.

Hypertension and future cardiovascular health in pediatric end-stage renal disease patients

BACKGROUND

There are now numerous studies that have documented an increased risk of cardiovascular morbidity and mortality in young adults who had childhood-onset end-stage renal disease (ESRD). Since the number of such patients surviving to adulthood is increasing, strategies to reduce this risk are urgently needed.

METHODS

The various risk factors contributing to adult cardiovascular disease in this population will be reviewed, with an emphasis on hypertension and its control. Data demonstrating the prevalence of hypertension in childhood chronic kidney disease as well as the results of improved blood pressure control in ESRD will also be presented.

CONCLUSIONS

Hypertension is exceedingly common in pediatric ESRD patients and frequently poorly controlled. Efforts to improve blood pressure control in this patient population could potentially reduce future cardiovascular morbidity and mortality.

Vitamin D deficiency and arterial wall stiffness in children with chronic kidney disease

Arterial wall stiffness is a recognized complication in children with chronic kidney disease (CKD). Vascular abnormalities in these patients are shown to predate cardiac abnormalities such as left ventricular hypertrophy and diastolic dysfunction. The etiology of vascular abnormalities in these patients currently is not clear. This study explored the relationship between various parameters of calcium-phosphorus metabolism including 25-hydroxy vitamin D and arterial wall stiffness in pediatric patients with CKD. This study investigated a cohort of 43 children with CKD who had no history of underlying congenital or structural cardiac disease. The Augmentation Index (AI), a measure of peripheral arterial reflective properties using radial artery tonometry, was used as an indirect measure of central aortic stiffness. Serum biochemical markers of calcium-phosphorus metabolism were simultaneously measured. Univariate testing showed that AI correlated with worsening kidney function. Serum 25-hydroxy vitamin D levels were low and correlated negatively with AI (r = -0.39; p < 0.05). Multiple regression analysis showed that 25-hydroxy vitamin D was the only significant independent predictor of increased central arterial stiffness in the subgroup of children receiving hemodialysis. No association was observed between AI and any other measured biochemical parameter of calcium-phosphorus metabolism. This is the first study to investigate pediatric patients with CKD that suggests an association between nutritional vitamin D deficiency and increased arterial stiffness in children with CKD. The pathophysiologic mechanisms of vitamin D that regulate increased arterial stiffness need to be integrated further in pediatric CKD patients.

Dyslipidemia in children with chronic kidney disease

Dyslipidemia, a known risk factor for atherosclerosis, is frequent among both adults and children with chronic kidney disease. Here, we describe the prevalence and pattern of dyslipidemia from a cross-sectional analysis of 391 children aged 1-16 years, enrolled in the multicenter Chronic Kidney Disease in Children (CKiD) study, with a median glomerular filtration rate (GFR), measured by the plasma disappearance of iohexol, of 43 ml/min per 1.73 m2. Multivariate analysis was applied to adjust for age, gender, body mass index (BMI), GFR, and the urinary protein/creatinine ratio. Proteinuria was in the nephrotic range in 44 and the BMI exceeded the 95th percentile in 57 patients of this cohort. Baseline lipid analysis found a high prevalence of hypertriglyceridemia in 126, increased non-HDL-C in 62, and reduced HDL-C in 83. Overall, 177 children had dyslipidemia, of whom 79 had combined dyslipidemia. Lower GFR was associated with higher triglycerides, lower HDL-C, and higher non-HDL-C. Nephrotic-range proteinuria was significantly associated with dyslipidemia and combined dyslipidemia. Compared with children with a GFR>50, children with a GFR<30 had significantly increased odds ratios for any dyslipidemia or for combined dyslipidemia. Hence, among children with moderate chronic kidney disease, dyslipidemia is common and is associated with lower GFR, nephrotic proteinuria, and non-renal factors including age and obesity.

Assessment of the cardiovascular system in pediatric chronic kidney disease: a pilot study

Long-term survival of children and adolescents with chronic kidney disease (CKD) is mainly limited by cardiovascular disease. Pediatric CKD patients (n = 26) on conservative treatment, dialysis and after renal transplantation were compared with healthy controls (n = 24) with respect to cardiovascular status. Mean baseline diameter of the brachial artery was significantly higher, and mean flow-mediated vasodilation (FMD) was significantly reduced, in CKD patients. CKD patients showed significantly increased left ventricular mass index, blood pressure (BP) values and age-related values of mean carotid intima-media thickness [intima-media thickness-standard deviation score (IMT-SDS)] compared with those of controls. Approximately 60% of patients presented with impaired FMD (< or = 5.79%), which was significantly associated with intima-media thickening, although only three patients (12%) presented with both, impaired FMD and increased age-related IMT. The latter was significantly associated with higher values for day-time BP. In contrast, duration and degree of CKD, mode of renal replacement therapy, homocysteine levels and concomitant medication showed no association with cardiovascular status. The majority of our pediatric CKD patients showed reduced endothelial function, which may have preceded the development of carotid arteriopathy. Therefore, routine assessment of FMD may be a useful tool to identify CKD patients at risk of progressive cardiovascular morbidity.

Amplification of atherosclerotic calcification and Mönckeberg's sclerosis: a spectrum of the same disease process

Autopsy studies have shown the near universal presence of fatty streaks and fibroatheromas in the general population from which chronic kidney disease (CKD) patients arise. The vast majority of CKD patients have multiple conventional cardiovascular risk factors. Atherosclerosis, once present, can predominantly manifest as medial calcification, which has been previously termed Mönckeberg's sclerosis. This term has also been used in rare cases to describe vascular calcinosis not related to CKD. This clarification is critical to advance the field in terms of pathological diagnosis and treatment of CKD bone and mineral disorder. Factors that appear to promote the osteoblastic transformation of vascular smooth muscle cells and enhance deposition of calcium hydroxyapatite crystals include phosphorus activation of the Pit-1 receptor, bone morphogenic proteins 2 and 4, leptin, endogenous 1,25 dihydroxy vitamin D, vascular calcification activating factor, and measures of oxidative stress. These entities work to accelerate the atherosclerotic process in CKD patients and may be future targets for diagnosis and treatment. Although conventional atherosclerotic risk factors should be optimally managed, it should be noted that trials of hydroxymethylglutaryl-CoA reductase inhibitors have failed to attenuate the rate of progressive vascular calcification as measured by computed tomography scans.

Arterial changes in children undergoing renal transplantation

INTRODUCTION

Pathological changes of large arterial walls and the heart have been described in patients with chronic renal failure. The aim of the study was to verify the incidence of arterial changes among our series of pediatric patients with end-stage renal disease undergoing transplantation.

PATIENTS AND METHODS

From January 2004 to December 2006, 26 patients (15 boys and 11 girls) of overall mean age of 13.12 years (range=3-27 years) underwent renal transplantation in our department. The pretransplant dialysis treatment was peritoneal in eight and hemodialysis in 18 cases. All patients were divided in two groups according to primary renal disease: group A were 18 patients with congenital urinary malformations; and group B, eight patients with acquired glomerular diseases. In each case, a sample of artery from both donor (aortic patch of kidney) and recipient (iliac patch of graft allocation) was obtained during renal transplantation. The donors were considered to be the control group.

RESULTS

Light microscopy showed pathological changes in 12/26 recipient arteries: nine showed light fragmentation of the internal elastic lamina; two, more severe fragmentations; and one, fragmentation of the internal elastic lamina associated with mucopolysaccharide deposits. Pathological changes were more evident in group A than B, but the difference was not significant (P> .05). Among the donor group, 11 patients showed light fragmentation of the internal elastic lamina, but there was no significant difference with the recipients (P> .05).

CONCLUSIONS

Among our group of patients, we observed only slight modifications of the arterial wall. These changes were nonspecific, similar to those in a control group of donors matched for age. A possible explanation of these findings may depend on the short time of dialysis before transplantation.

Accelerated atherosclerotic calcification and Monckeberg's sclerosis: a continuum of advanced vascular pathology in chronic kidney disease

Autopsy studies have demonstrated the near universal presence of fatty streaks and fibroatheromas in the general population from which patients with chronic kidney disease (CKD) arise. The vast majority of patients with CKD have multiple conventional cardiovascular risk factors. Vascular atherosclerotic calcification develops in most patients as they transition from the general population to significant CKD as part of cholesterol crystallization within atherosclerotic lesions. Once present, however, atherosclerotic medial calcification can become prominent and has been previously identified as Mönckeberg's sclerosis. A unifying concept supported by the preponderance of pathologic evidence contends that Mönckeberg's sclerosis is a manifestation of accelerated atherosclerosis in patients with CKD. The term has also been used in rare cases to describe vascular calcinosis not related to CKD. This clarification is critical to advance the field in terms of pathologic diagnosis and treatment of CKD bone and mineral disorder. Factors that seem to promote the osteoblastic transformation of vascular smooth muscle cells and enhance deposition of calcium hydroxyapatite crystals include phosphorus activation of the Pit-1 receptor, bone morphogenic proteins 2 and 4, leptin, endogenous 1,25 dihydroxyvitamin D, vascular calcification activating factor, and measures of oxidative stress. These entities work to accelerate the atherosclerotic process in patients with CKD and may be future targets for diagnosis and treatment because randomized trials with hydroxymethylglutaryl-CoA reductase inhibitors have failed to attenuate the rate of progressive vascular calcification.

Determinants of the intima-media thickness in children and adolescents with chronic kidney disease

The aim of the study was to evaluate changes in the arterial wall in children with chronic kidney disease (CKD). We studied 60 patients: 32 with stages 2-4 CKD [chronic renal failure (CRF)], 28 with stage 5 CKD [end-stage renal disease (ESRD)], and 43 controls (C). The evaluated parameters included intima-media thickness (IMT) of the carotid arteries, bone mineral density (BMD), serum lipid levels, and parameters of the calcium-phosphorus metabolism. Patients were divided into two groups: group 1 with normal arteries, and group 2 with arterial changes. The highest serum fetuin A level was found in group 1 compared with groups 2 and C. A negative correlation between IMT and fetuin A level was found. In patients with ESRD, a positive correlation of IMT with phosphorus level and age and a negative correlation with cyclase-activating parathyroid hormone and cyclase inhibiting parathyroid hormone (CAP/CIP) ratio was observed. Multiple linear regression showed that lower fetuin-A and alkaline phosphatase (AP) levels and higher lumbar spine BMD independently predicted higher IMT. Arterial wall changes in children with CKD were related to lower fetuin A and AP level and higher BMD. Low CAP/CIP and high phosphorus level may also be significant factors for arterial changes in patients with ESRD.

What parathyroid hormone levels should we aim for in children with stage 5 chronic kidney disease; what is the evidence?

The bone disease that occurs as a result of chronic kidney disease (CKD) is not only debilitating but also linked to poor growth and cardiovascular disease. It is suspected that abnormal bone turnover is the main culprit for these poor outcomes. Plasma parathyroid hormone (PTH) levels are used as a surrogate marker of bone turnover, and there is a small number of studies in children that have attempted to identify the range of PTH levels that correlates with normal bone histology. It is clear that high PTH levels are associated with high bone turnover, although the range is wide. However, the ability of PTH levels to distinguish between low and normal bone turnover is less clear. This is an important issue, because current guidelines for calcium and phosphate management are based upon there being an "optimum" range for PTH. This editorial takes a critical look at the evidence upon which these recommendations are based.

Cardiovascular complications of pediatric chronic kidney disease

Cardiovascular disease (CVD) mortality is a leading cause of death in adult chronic kidney disease (CKD), with exceptionally high rates in young adults, according to the Task Force on Cardiovascular Disease. Recent data indicate that cardiovascular complications are already present in children with CKD. This review summarizes the current literature on cardiac risk factors, mortality and morbidity in children with CKD.

Lipoprotein metabolism in chronic renal insufficiency

Chronic renal insufficiency (CRI) is associated with a characteristic dyslipidemia. Findings in children with CRI largely parallel those in adults. Moderate hypertriglyceridemia, increased triglyceride-rich lipoproteins (TRL) and reduced high-density lipoproteins (HDL) are the most usual findings, whereas total and low-density lipoprotein cholesterol (LDL-C) remain normal or modestly increased. Qualitative abnormalities in lipoproteins are common, including small dense LDL, oxidized LDL, and cholesterol-enriched TRL. Measures of lipoprotein lipase and hepatic lipase activity are reduced, and concentrations of apolipoprotein C-III are markedly elevated. Still an active area of research, major pathophysiological mechanisms leading to the dyslipidemia of CRI include insulin resistance and nonnephrotic proteinuria. Sources of variability in the severity of this dyslipidemia include the degree of renal impairment and the modality of dialysis. The benefits of maintaining normal body weight and physical activity extend to those with CRI. In addition to multiple hypolipidemic pharmaceuticals, fish oils are also effective as a triglyceride-lowering agent, and the phosphorous binding agent sevelamer also lowers LDL-C. Emerging classes of hypolipidemic agents and drugs affecting sensitivity to insulin may impact future treatment. Unfortunately, cardiovascular benefit has not been convincingly demonstrated by any trial designed to study adults or children with renal disease. Therefore, it is not possible at this time to endorse general recommendations for the use of any agent to treat dyslipidemia in children with chronic kidney disease.

Cardiovascular risk reduction in high-risk pediatric patients: a scientific statement from the American Heart Association Expert Panel on Population and Prevention Science; the Councils on Cardiovascular Disease in the Young, Epidemiology and Prevention, Nutrition, Physical Activity and Metabolism, High Blood Pressure Research, Cardiovascular Nursing, and the Kidney in Heart Disease; and the Interdisciplinary Working Group on Quality of Care and Outcomes Research

Although for most children the process of atherosclerosis is subclinical, dramatically accelerated atherosclerosis occurs in some pediatric disease states, with clinical coronary events occurring in childhood and very early adult life. As with most scientific statements about children and the future risk for cardiovascular disease, there are no randomized trials documenting the effects of risk reduction on hard clinical outcomes. A growing body of literature, however, identifies the importance of premature cardiovascular disease in the course of certain pediatric diagnoses and addresses the response to risk factor reduction. For this scientific statement, a panel of experts reviewed what is known about very premature cardiovascular disease in 8 high-risk pediatric diagnoses and, from the science base, developed practical recommendations for management of cardiovascular risk.

Carotid artery thickness in children and young adults with end stage renal disease

Atherosclerosis is a major cause of morbidity and mortality for ESRD patients and we have little knowledge about the presence and risk factors of atherosclerosis in children with CRF. The measurement of carotid artery intima-media thickness (cIMT) using high-resolution ultrasonography is suggested as an excellent marker of subclinical atherosclerosis. In this study, we aimed to investigate the presence of atherosclerosis and to determine the relationship between atherosclerosis and some risk factors in children and young adults with ESRD. Thirty-four patients with ESRD and 20 controls were included in this study. The measurement of cIMT was performed by using a linear B-mode 7.5-MHz ultrasound transducer. We determined anemia, abnormal calcium/phosphate metabolism, hyperhomocysteinemia, hypertriglyceridemia and increased lipoprotein (a) levels in the ESRD group. The cIMT in the ESRD group was higher than in the control group (P<0.05). SBP, DBP, MAP, LVMI and LVH prevalence were statistically higher in the ESRD group (P<0.05). There were significant positive correlations between cIMT and LVMI, MBP, whereas a significant negative correlation was determined between cIMT and PTH in the ESRD group (P<0.05). When a multiple linear regression analysis was performed with cIMT as a dependent variable and LVMI, MBP, PTH, as independent variables, a significant positive correlation was determined between cIMT and LVMI (P<0.05). In conclusion, we think that arteriopathy occurs in children with ESRD. Left ventricular hypertrophy and hypertension may associate with vascular changes in children and young adults with ESRD. Further investigations are necessary to explain association of LVMI index with cIMT.

Minimizing bone abnormalities in children with renal failure

Renal osteodystrophy (ROD), a metabolic bone disease accompanying chronic renal failure (CRF), is a major clinical problem in pediatric nephrology. Growing and rapidly remodeling skeletal systems are particularly susceptible to the metabolic and endocrine disturbances in CRF. The pathogenesis of ROD is complex and multifactorial. Hypocalcemia, phosphate retention, and low levels of 1,25 dihydroxyvitamin D(3) related to CRF result in disturbances of bone metabolism and ROD. Delayed diagnosis and treatment of bone lesions might result in severe disability. Based on microscopic findings, renal bone disease is classified into two main categories: high- and low-turnover bone disease. High-turnover bone disease is associated with moderate and severe hyperparathyroidism. Low-turnover bone disease includes osteomalacia and adynamic bone disease. The treatment of ROD involves controlling serum calcium and phosphate levels, and preventing parathyroid gland hyperplasia and extraskeletal calcifications. Serum calcium and phosphorus levels should be kept within the normal range. The calcium-phosphorus product has to be <5 mmol(2)/L(2) (60 mg(2)/dL(2)). Parathyroid hormone (PTH) levels in children with CRF should be within the normal range, but in children with end-stage renal disease PTH levels should be two to three times the upper limit of the normal range. Drug treatment includes intestinal phosphate binding agents and active vitamin D metabolites. Phosphate binders should be administered with each meal. Calcium carbonate is the most widely used intestinal phosphate binder. In children with hypercalcemic episodes, sevelamer, a synthetic phosphate binder, should be introduced. In children with CRF, ergocalciferol (vitamin D(2)), colecalciferol (vitamin D(3)), and calcifediol (25-hydroxyvitamin D(3)) should be used as vitamin D analogs. In children undergoing dialysis, active vitamin D metabolites alfacalcidol (1alpha-hydroxy-vitamin D(3)) and calcitriol (1,25 dihydroxyvitamin D(3)) are applied. In recent years, a number of new drugs have emerged that hold promise for a more effective treatment of bone lesions in CRF. This review describes the current approach to the diagnosis and treament of ROD.

Cardiovascular Risk Reduction in High-Risk Pediatric Patients

Although for most children the process of atherosclerosis is subclinical, dramatically accelerated atherosclerosis occurs in some pediatric disease states, with clinical coronary events occurring in childhood and very early adult life. As with most scientific statements about children and the future risk for cardiovascular disease, there are no randomized trials documenting the effects of risk reduction on hard clinical outcomes. A growing body of literature, however, identifies the importance of premature cardiovascular disease in the course of certain pediatric diagnoses and addresses the response to risk factor reduction. For this scientific statement, a panel of experts reviewed what is known about very premature cardiovascular disease in 8 high-risk pediatric diagnoses and, from the science base, developed practical recommendations for management of cardiovascular risk.

Cardiovascular disease in children with chronic renal failure

Cardiovascular disease (CVD), including atherosclerosis, hypertension, myocardial infarction, and cerebrovascular accidents, constitutes an important cause of morbidity and mortality in adults with chronic kidney disease (CKD). However, evidence has been accumulating over the past several years that children and young adults with CKD also experience significant cardiovascular complications. Studies in the United States and Europe have shown that CVD is a leading cause of death in young adults diagnosed with CKD in childhood. Risk factors include hypertension, dyslipidemia, anemia, and abnormal calcium-phosphorus metabolism, all of which are present in many children with CKD. Although improved control of uremia and treatment of traditional and nontraditional cardiovascular risk factors have proved to be beneficial in adults with CKD, no such data exist for children. The NIH is currently conducting a large-scale, prospective observational study of children with CKD that should help to elucidate the role of CVD in the progression of CKD in children and what interventions might reduce the risk of cardiovascular complications in these young patients.

Assessing cardiovascular risk in children with chronic kidney disease. B-type natriuretic peptide: a potential new marker

Elevated plasma B-type natriuretic peptide (BNP) level is a hallmark of altered left ventricular (LV) structure and function. Measurement of circulating BNP has proved to be a sensitive and specific diagnostic test for congestive heart failure (CHF) and coronary syndrome in adults. Further, BNP levels constitute a strong predictive marker for future cardiovascular (CV) events. In high CV risk populations, such as adults with hypertension or chronic kidney disease (CKD), increased BNP predicts CV morbidity and mortality in symptomatic or asymptomatic patients. However, caution is needed in interpreting plasma BNP levels, as they increase with both age and decreased renal function. Despite increasing evidence of the value of BNP in the medical literature in adults, data in children are limited to those with congenital heart disease. It is appropriate to analyze the potential application of this tool in children with CKD, a well-known factor for CV disease.

Cardiovascular disease in children with chronic kidney disease

In children with end-stage renal disease (ESRD), cardiovascular disease (CVD) mortality has not changed for the past 3 decades. Cardiac disease remains the second most common cause of death. Recent data demonstrate a high incidence and prevalence of traditional and chronic kidney disease (CKD)-related CVD risk factors in children. Early markers of cardiomyopathy, such as left ventricular hypertrophy (LVH) and left ventricular dysfunction (LV dysfunction), and early markers of atherosclerosis, such as increased carotid artery intima-media thickness (IMT) and carotid arterial wall stiffness, are frequently found in this patient population. Early identification of modifiable risk factors and treatment of asymptomatic CVD might lead to decrease of cardiovascular morbidity and mortality in young adults who developed CKD during childhood.

Obesity and renal transplant outcome: a report of the North American Pediatric Renal Transplant Cooperative Study

OBJECTIVE

Obesity is increasing in the end-stage renal disease population. Studies that have evaluated the effect of obesity on transplant outcomes in adults have yielded varying results. This issue has received little attention in the pediatric population.

METHODS

We performed a retrospective study of the effect of obesity on pediatric renal transplant outcomes using the North American Pediatric Renal Transplant Cooperative Study database. Registry data from 1987 through 2002 on 6658 children aged 2 to 17 years were analyzed. Obesity was defined by a BMI >95th percentile for age.

RESULTS

Overall, 9.7% were obese with an increase noted in recent years (12.4% after 1995 vs 8% before 1995). Obese children were significantly younger and shorter and had been on dialysis for a longer time than nonobese children. There was no significant difference in the overall patient and allograft survival between the 2 groups. However, obese children aged 6 to 12 years had higher risk for death than nonobese patients (adjusted relative risk: 3.65 for living donor; adjusted relative risk: 2.94 for cadaver), and death was more likely as a result of cardiopulmonary disease (27% in obese vs 17% in nonobese). Overall, graft loss as a result of thrombosis was more common in obese as compared with nonobese (19% vs 10%).

CONCLUSIONS

Obesity is an increasing problem in children who present for transplantation and may have an adverse effect on allograft and patient survival.

Cardiovascular complications in pediatric end-stage renal disease

Mortality from end-stage renal disease (ESRD) is often due to cardiac causes. Although cardiovascular complications of ESRD have long been recognized, only recently has the presence of traditional cardiovascular risk factors been associated with late cardiovascular complications. This review presents a history of cardiac involvement in ESRD, the pathophysiology of accelerated atherosclerosis and left ventricular hypertrophy, and a summary of the literature on cardiovascular risk assessment in children. Techniques for non-invasive assessment of cardiac end-organ injury are also discussed. Recommendations for monitoring of risk factors and treatment in the pediatric ESRD population are presented.

Effect of dialysis modality on plasma fibrinogen concentration: A meta-analysis

BACKGROUND

Concentrations of plasma fibrinogen, a vascular risk factor, tend to be greater in patients on peritoneal dialysis (PD) than hemodialysis (HD) therapy, like concentrations of serum cholesterol, lipoprotein(a), and transthyretin, despite the substantial loss of protein during PD. Worse vascular outcome has been noted in PD patients compared with HD patients in several studies.

METHODS

In this study, the mean difference in plasma fibrinogen levels (PD-HD) was quantified by means of meta-analysis of mean differences found in 12 cohorts with both PD and HD patients (set 1; N = 630) by using a fixed-effects model and meta-analysis of mean fibrinogen values reported in 30 cohorts of patients on a single dialysis modality (set 2; 8 PD cohorts, 22 HD cohorts; N = 2,096) by using a mixed model.

RESULTS

On meta-analysis, the weighted mean difference (PD-HD) was 105 mg/dL (95% confidence interval [CI], 86 to 124 [3.1 micromol/L; 95% CI, 2.5 to 3.6]) in set 1 and 103 mg/dL (95% CI, 53 to 153 [3.0 micromol/L; 95% CI, 1.6 to 4.5) in set 2.

CONCLUSION

Like other vascular risk factors, such as cholesterol and lipoprotein(a), plasma fibrinogen level is markedly greater in PD than HD patients, with an approximate difference of 100 mg/dL [2.9 mumol/L]. Different plasma reference ranges for fibrinogen need to be defined for PD and HD patients. The mechanism for the difference and the possible role of hyperfibrinogenemia in worsening vascular disease in PD patients deserve study.

Pathomechanisms and the diagnosis of arterial hypertension in pediatric renal allograft recipients

Arterial hypertension is common in pediatric renal allograft recipients. While the causes are multifactorial, including chronic graft rejection, immunosuppressive therapy, and renal vascular disorders, the effect of hypertension on renal allograft function is detrimental. As in adults, if not treated early and aggressively, hypertension may lead to cardiovascular damage and graft failure. Pathophysiological changes in the arteries and kidney af-ter renal transplantation and the impact of receptor regulation have not been studied extensively in children. For identifying children with hypertension following renal transplantation casual blood pressure measurements do not accurately reflect average arterial blood pressure and circadian blood pressure rhythm. Ambulatory 24-h blood pressure monitoring should regularly be applied in trans-plant patients. The purpose of this review is to analyze pathophysiological aspects of risk factors for arterial hypertension and underline the importance of regular blood pressure monitoring and early therapeutic intervention.

The spectrum of cardiovascular disease in children with predialysis chronic kidney disease

Cardiovascular disease is the major cause of mortality in adults and children on chronic dialysis and in adults after kidney transplantation. Cardiovascular disease burden and cardiovascular mortality are high in adults with chronic kidney disease. The early development of cardiovascular disease risk factors, some of which are modifiable, largely explain this phenomenon. Limited data are available on the prevalence of chronic kidney disease in children, the prevalence of cardiovascular disease in children with chronic kidney disease, and the prevalence of cardiovascular disease risk factors in these patients. This article summarizes the current knowledge of the prevalence of cardiovascular disease and of cardiovascular disease risk factors in pediatric patients with predialysis chronic kidney disease. Long-term prospective studies are needed to determine the impact of early identification and treatment of cardiovascular disease and its risk factors on the natural history of cardiovascular disease in children with chronic kidney disease.

Clinical practice guidelines for managing dyslipidemias in kidney transplant patients: a report from the Managing Dyslipidemias in Chronic Kidney Disease Work Group of the National Kidney Foundation Kidney Disease Outcomes Quality Initiative

The incidence of cardiovascular disease (CVD) is very high in patients with chronic kidney (CKD) disease and in kidney transplant recipients. Indeed, available evidence for these patients suggests that the 10-year cumulative risk of coronary heart disease is at least 20%, or roughly equivalent to the risk seen in patients with previous CVD. Recently, the National Kidney Foundation's Kidney Disease Outcomes Quality Initiative (K/DOQI) published guidelines for the diagnosis and treatment of dyslipidemias in patients with CKD, including transplant patients. It was the conclusion of this Work Group that the National Cholesterol Education Program Guidelines are generally applicable to patients with CKD, but that there are significant differences in the approach and treatment of dyslipidemias in patients with CKD compared with the general population. In the present document we present the guidelines generated by this workgroup as they apply to kidney transplant recipients. Evidence from the general population indicates that treatment of dyslipidemias reduces CVD, and evidence in kidney transplant patients suggests that judicious treatment can be safe and effective in improving dyslipidemias. Dyslipidemias are very common in CKD and in transplant patients. However, until recently there have been no adequately powered, randomized, controlled trials examining the effects of dyslipidemia treatment on CVD in patients with CKD. Since completion of the K/DOQI guidelines on dyslipidemia in CKD, the results of the Assessment of Lescol in Renal Transplantation (ALERT) Study have been presented and published. Based on information from randomized trials conducted in the general population and the single study conducted in kidney transplant patients, these guidelines, which are a modified version of the K/DOQI dyslipidemia guidelines, were developed to aid clinicians in the management of dyslipidemias in kidney transplant patients. These guidelines are divided into four sections. The first section (Introduction) provides the rationale for the guidelines, and describes the target population, scope, intended users, and methods. The second section presents guidelines on the assessment of dyslipidemias (guidelines 1-3), while the third section offers guidelines for the treatment of dyslipidemias (guidelines 4-5). The key guideline statements are supported mainly by data from studies in the general population, but there is an urgent need for additional studies in CKD and in transplant patients. Therefore, the last section outlines recommendations for research.