Background and objectives: Although lesions of renal osteodystrophy have traditionally been defined by bone turnover, alterations in skeletal mineralization and volume are also prevalent and may contribute to significant morbidity in patients with chronic kidney disease (CKD). The study presented here was undertaken to compare the traditional spectrum of renal osteodystrophy defined by bone turnover to a new classification system that includes T (turnover), M (mineralization), and V (volume) and to determine the value of biochemical parameters as predictors of specific TMV lesions. Design, setting, participants, & measurements: Pediatric patients (n = 161) treated with peritoneal dialysis were enrolled into the study. Results: Increased bone turnover and abnormal mineralization were prevalent (57% and 48%, respectively); bone volume was normal or increased in all subjects. Predictive algorithms for different skeletal diagnoses were established by Classification and regression tree analysis. Serum parathyroid hormone (PTH) less than 400 pg/ml in combination with alkaline phosphatase values less than 400 IU/L provided the highest correct prediction rate for patients with both normal bone turnover and normal mineralization. Levels of PTH were higher and serum calcium levels were lower in patients with defective mineralization, irrespective of bone turnover. Conclusions: Although no single biochemical marker is able to provide a complete assessment of renal osteodystrophy, a combination of serum calcium, alkaline phosphatase, and PTH levels may lead to a more precise noninvasive assessment of turnover and mineralization abnormalities in this population.

Summary: Background and objectives: Left ventricular hypertrophy (LVH) is an independent risk factor and an intermediate end point of dialysis-associated cardiovascular comorbidity. We utilized a global pediatric registry to assess the prevalence, incidence, and predictors of LVH as well as its evolution in the longitudinal follow-up in dialyzed children. Design, setting, participants, & measurements: Cross-sectional echocardiographic, clinical, and biochemical data were evaluated in 507 children on peritoneal dialysis (PD), and longitudinal data were evaluated in 128 patients. The 95^th percentile of LV mass index relative to height age was used to define LVH. Results: The overall LVH prevalence was 48.1%. In the prospective analysis, the incidence of LVH developing de novo in patients with normal baseline LV mass was 29%, and the incidence of regression from LVH to normal LV mass 40% per year on PD. Transformation to and regression from concentric LV geometry occurred in 36% and 28% of the patients, respectively. Hypertension, high body mass index, use of continuous ambulatory peritoneal dialysis, renal disease other than hypo/dysplasia, and hyperparathyroidism were identified as independent predictors of LVH. The use of renin-angiotensin system (RAS) antagonists and high total fluid output (sum of urine and ultrafiltration) were protective from concentric geometry. The risk of LVH at 1 year was increased by higher systolic BP standard deviation score and reduced in children with renal hypo/dysplasia. Conclusions: Using height-adjusted left ventricular mass index reference data, LVH is highly prevalent but less common than previously diagnosed in children on PD. Renal hypo/dysplasia is protective from LVH, likely because of lower BP and polyuria. Hypertension, fluid overload, and hyperparathyroidism are modifiable determinants of LVH.

We aimed to clarify arteriosclerotic risk and to document possible relationships between cardiovascular risk factors and echocardiographic parameters in paediatric peritoneal dialysis (PD) patients. M-mode/Doppler/tissue Doppler echocardiographic studies and lipid/lipoproteins, homocysteine, high-sensitivity C-reactive protein (HS-CRP) levels and carotid intima-media thickness (CIMT) were determined in 59 patients (age: 14.2 +/- 4.5 years) and in 36 healthy subjects. Structural and functional cardiac abnormalities were observed in patients on maintenance dialysis. Increased left ventricular mass index (LVMI, P = 0.000), relative wall thickness (P = 0.000), myocardial performance index (MPI, P = 0.000) were documented in the patients. Lipoprotein (a) (P = 0.000), homocysteine (P = 0.001), HS-CRP (P = 0.000) and CIMT (P = 0.000) were significantly elevated in the patients. Left ventricular hypertrophy (LVH) was prevalent in 68% of the patients. Patients with LVH had higher levels of HS-CRP (P = 0.001) and CIMT (P = 0.028) than those without LVH. Haemoglobin was an independent predictor of LVMI (beta: -8.9, P = 0.001), while residual diuresis and CIMT were independent predictors of diastolic dysfunction (beta: -0.45, P = 0.034 and beta: 5.90, P = 0.008, respectively). Albumin (beta: -0.72, P = 0.018) and Kt/V urea (beta: -0.48, P = 0.012) were significant predictors of CIMT. There were positive correlations between LVMI and CIMT. HS-CRP was positively correlated with LVMI as well as CIMT. Elevated levels of atherosclerotic/ inflammatory risk factors, low haemoglobin levels and loss of residual renal function and their negative effects on heart are of remarkable importance in paediatric patients on maintenance peritoneal dialysis. Achieving recommended targets for haemoglobin, blood pressure and Kt/V urea, preserving residual renal function as well as managing inflammation and subsequent arteriosclerosis is obviously essential to improve the patients' prognosis.

Background: There is no consensus regarding the timing of dialysis therapy initiation for end-stage kidney disease (ESKD) in children. As studies investigating the association between timing of dialysis initiation and clinical outcomes are lacking, we aimed to study this relationship in a cohort of European children who started maintenance dialysis treatment.Methods: We used data on 2963 children from 21 different countries included in the European Society of Pediatric Nephrology/European Renal Association–European Dialysis and Transplant Association Registry who started renal replacement therapy before 18 years of age between 2000 and 2014. We compared two groups according to the estimated glomerular filtration rate (eGFR) at start: eGFR ≥8 mL/min/1.73 m2 (early starters) and eGFR <8 mL/min/1.73 m2 (late starters). The primary outcomes were patient survival and access to transplantation. Secondary outcomes were growth and cardiovascular risk factors. Sensitivity analyses were performed to account for selection- and lead time-bias.Results: The median eGFR at the start of dialysis was 6.1 for late versus 10.5 mL/min/1.73 m2 for early starters. Early starters were older [median: 11.0, interquartile range (IQR): 5.7–14.5 versus 9.4, IQR: 2.6–14.1 years]. There were no differences observed between the two groups in mortality and access to transplantation at 1, 2 and 5 years of follow-up. One-year evolution of height standard deviation scores was similar among the groups, whereas hypertension was more prevalent among late initiators. Sensitivity analyses resulted in similar findings.Conclusions: We found no evidence for a clinically relevant benefit of early start of dialysis in children with ESKD. Presence of cardiovascular risk factors, such as high blood pressure, should be taken into account when deciding to initiate or postpone dialysis in children with ESKD, as this affects the survival.