To characterize the distribution of blood pressure (BP), prevalence and risk factors for hypertension in pediatric chronic kidney disease (CKD), we conducted a cross-sectional analysis of baseline BP's in 432 children (mean age 11y; 60% male; mean glomerular filtration rate [GFR] 44 ml/min/1.73m2) enrolled in the Chronic Kidney Disease in Children cohort study. BP's were obtained using an aneroid sphygmomanometer. GFR was measured by iohexol disappearance. Elevated BP was defined as BP≥90th percentile for age, gender and height. Hypertension was defined as BP≥95th percentile or as self-reported hypertension plus current treatment with antihypertensive medications. For systolic BP, 14% were hypertensive and 11% were pre-hypertensive (BP 90-95th percentile); 68% of subjects with elevated SBP were taking antihypertensive medications. For diastolic BP, 14% were hypertensive, and 9% were pre-hypertensive; 53% of subjects with elevated DBP were taking antihypertensive medications. 54% of subjects had either systolic or diastolic BP≥95th percentile or a history of hypertension plus current antihypertensive use. Characteristics associated with elevated BP included black race, shorter duration of CKD, absence of antihypertensive medication use, and elevated serum potassium. Among subjects receiving antihypertensive treatment, uncontrolled BP was associated with male sex, shorter CKD duration and absence of ACE inhibitor or ARB use. 37% of children with CKD had either elevated systolic or diastolic BP, and 39% of these were not receiving antihypertensives, indicating that hypertension in pediatric CKD may be frequently under- or even un-treated. Treatment with ACE inhibitors or ARB's may improve BP control in these patients.

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Background and objectives: Proteinuria is associated with chronic kidney disease (CKD), and heavy proteinuria predicts a rapid decline in kidney function. However, the epidemiologic distribution of this important biomarker study is not well described in the pediatric CKD population.Design, setting, participants & measurements: This cross-sectional study of North American children with CKD examined the association of proteinuria among the baseline clinical variables in the cohort. Urinary protein-to-creatinine ratios (Up/c) were used to measure level of proteinuria.Results: Of the 419 subjects studied, the median GFR as measured by iohexol disappearance (iGFR) was 42 ml/min per 1.73 m 2 , median duration of CKD was six yr, and glomerular diseases accounted for 22% of the CKD diagnoses. Twenty-four percent of children had normal range (Up/c <0.2), 62% had significant, and 14% had nephrotic-range proteinuria (Up/c >2.0). A decrease in iGFR was associated with an increase in Up/c. At any level of GFR, a higher Up/c was associated with a glomerular cause of CKD and non-Caucasian race. Among subjects with a glomerular cause of CKD, Up/c was lower in subjects reporting utilization of renin-angiotensin system (RAS) antagonists (median Up/c ‫؍‬ 0.93) compared with those who did not (median Up/c ‫؍‬ 3.78).Conclusions: Proteinuria is associated with level of iGFR, cause of CKD, and race. The longitudinal study design of Chronic Kidney Disease in Children (CKiD) cohort study and the large number of subjects being studied has created an opportunity to better define the association between proteinuria and CKD progression.