Cardiometabolic Risk Factors, Metabolic Syndrome, and Chronic Kidney Disease Progression in Children.

OBJECTIVE: To estimate the prevalence of metabolic syndrome (MetS) and examine its association with chronic kidney disease progression in children enrolled in the Chronic Kidney Disease in Children study. STUDY DESIGN: MetS was defined as being overweight or obese and having ≥2 cardiometabolic risk factors (CMRFs). Incidence and prevalence of MetS were assessed using pairs of visits approximately 2 years apart. RESULTS: A total of 799 pairs of person-visits (contributed by 472 children) were included in the final analysis. Of these, 70% had a normal body mass index (BMI), 14% were overweight, and 16% were obese. At the first visit, the prevalence of MetS in the overweight group was 40% and in the obese group was 60%. In adjusted models, annual percent estimated glomerular filtration rate decline in those who had normal BMI and incident or persistent multiple CMRFs or those with persistent MetS was -6.33%, -6.46%, and -6.08% (respectively) compared with children who never had multiple CMRFs (-3.38%, P = .048, .045, and .036, respectively). Children with normal BMI and incident multiple CMRFs and those with persistent MetS had approximately twice the odds of fast estimated glomerular filtration rate decline (>10% per year) compared with those without multiple CMRFs and normal BMI. CONCLUSION: Children with chronic kidney disease have a high prevalence of MetS. These children as well as those with normal BMI but multiple CMRFs experience a faster decline in kidney function.

Subclinical systolic dysfunction in pediatric patients with chronic kidney disease.

OBJECTIVES: Midwall shortening (mwSF) is thought to be a more accurate measure of myocardial performance in the presence of left ventricular hypertrophy (LVH). We examined mwSF in pediatric patients with varying degrees of chronic kidney disease (CKD). STUDY DESIGN: Fifty-seven children with CKD stages 2 to 4, 25 who were undergoing hemodialysis and 49 who were transplant recipients, were compared with 35 healthy control subjects. Left ventricular (LV) geometry and indices of LV function were assessed echocardiographically. RESULTS: There were no significant differences in LV contractility or endocardial shortening fraction between patients and control subjects. Yet, patients undergoing hemodialysis had significantly lower mwSF compared with control subjects (P < .01) and patients with stage 2 to 4 CKD (P < .01). Renal transplant patients had lower mwSF compared with control subjects (P < .01). The prevalence of abnormal mwSF (ie, <16) was significantly higher in patients undergoing hemodialysis (40%) compared with patients who were renal transplant recipeints (12%) and patients with CKD stages 2 to 4 (9%; P = .03). With stepwise regression, mwSF was demonstrated to be predicted by using relative wall thickness (P < .0001), dialysis group (P = .005), and endocardial shortening fraction (P = .001; model R(2) = 0.86). CONCLUSIONS: Children undergoing maintenance hemodialysis and children with concentric LVH have subclinical systolic dysfunction, which might be an indicator for the development of more severe cardiac disease.

Progression of left ventricular hypertrophy in children with early chronic kidney disease: 2-year follow-up study.

OBJECTIVE: To determine the prevalence and incidence of left ventricular hypertrophy (LVH) and LV geometry and identify variables associated with LV mass (LVM) growth and development of LVH in children and adolescents with chronic kidney disease (CKD). STUDY DESIGN: A 2-year longitudinal study of children with CKD (glomerular filtration rate [GFR] 15-89 mL/minute/1.73 m2). Thirty-one subjects had baseline and repeated echocardiography. RESULTS: Six (19%) of 31 children had LVH at baseline; the prevalence of LVH increased to 39% at 2-year follow-up. Eccentric LVH was the most common geometric pattern throughout the study. Among 25 children with initially normal LVM index, 8 (32%) developed new LVH. Children with incident LVH had significantly higher mean parathyroid hormone (iPTH), lower hemoglobin and calcium levels at baseline, and significantly larger increase in iPTH during a follow-up than children with normal LVM index. Stepwise regression analysis showed that lower initial LVM index and hemoglobin level and interval increase in iPTH and nighttime systolic blood pressure (SBP) load during a follow-up independently predicted interval increase in LVM index. CONCLUSIONS: LVH progresses in children during early stages of CKD. More aggressive control of anemia, BP, and hyperparathyroidism might be important in preventing the development of LVH in these patients.

Early posttransplantation hypertension and poor long-term renal allograft survival in pediatric patients.

OBJECTIVE: To evaluate the effect of early hypertension on long-term allograft survival in children with kidney transplantation. STUDY DESIGN: Data from a total of 159 patients (mean age, 12.8+/-4.8 years) who underwent kidney transplantation between 1978 and 1998 and whose allograft was functioning for at least 1 year were analyzed retrospectively. Patients were divided according to the presence of hypertension within the first year after transplantation. Primary outcome was time of allograft failure (death, return to dialysis, or retransplantation). RESULTS: Kaplan-Meier analysis showed that systolic (P<.0001) and diastolic (P=.016) hypertension was associated with overall worse allograft survival. Children with systolic hypertension had a significantly higher graft failure rate regardless of the type of donor, cause of kidney failure, presence or absence of acute rejection, and allograft function at 1 year after transplantation. The multivariate Cox regression model proved that systolic hypertension was a significant and independent risk factor for poor graft survival (hazard ratio [HR], 1.79; P<.0001). Other predictors included allograft function at 1 year after transplantation (HR, 0.97; P<.0001), acquired cause of end-stage kidney disease (HR, 1.96; P=.01) and age <6 years (HR, 2.61; P=.045). CONCLUSIONS: Early posttransplantation systolic hypertension strongly and independently predicts poor long-term graft survival in pediatric patients.