Indicator Details — Children and Adolescents: Percentage of Pediatric CKD Patients with Proteinuriaa
Data Sources
 
Stratification and Year Choices:

  Source
  • CKiD

  Chart Format


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Footnotes:
a Proteinuria was defined by the urinary protein/creatinine ratio (Up/c) as: normal, Up/c<0.2 (or 200 mg/g); significant, Up/c 0.2-2 (or 200-2,000 mg/g); and nephrotic, Up/c>2 (or 2,000 mg/g). Non-white, African-American, multi-racial or other; GD, glomerular diagnosis. P-values by Cochran-Armitage test for trends or Spearman rank-correlation. Adapted from Wong et al.(2009).




Overall, fewer than one-quarter (24%) of North American pediatric CKD patients had proteinuria in the normal range; 62% had significant proteinuria and 14% had proteinuria in the nephrotic range.

Non-white patients had higher levels of proteinuria than white pediatric CKD patients (18.8% vs. 12.3% in the nephrotic range, respectively); similarly, patients with glomerular CKD diagnoses had higher levels than those without these diagnoses (31.9% vs. 9.5% in the nephrotic range, respectively)

The proportion with proteinuria also significantly increased with CKD stage, with significant or nephrotic-range proteinuria in 61.9%, 76.9% and 88.7% of those in CKD stage 1 or 2, stage 3 or stage 4, respectively.
Chart Explanation: Overall, fewer than one-quarter (24%) of pediatric CKD patients had proteinuria in the normal range; 62% had significant proteinuria and 14% had proteinuria in the nephrotic range. The distribution did not differ by gender (note that ~60-62% of pediatric CKD patients were male, regardless of proteinuria category; this differs from adult CKD patients, in whom females are the majority). Non-white patients and patients with glomerular CKD diagnoses were more likely to have significant or nephrotic-range proteinuria than their counterparts who were white and with another CKD diagnosis, respectively. The proportion with proteinuria also significantly increased with CKD stage, as defined by measured iohexol GFR.
The Chronic Kidney Disease in Children (CKiD) study is a prospective observational study of an estimated 500 children (1-16 years old) at 48 North American centers with varying degrees of CKD severity, which was designed to measure consequences in pediatric CKD patients. As with all cohort studies, recruitment bias and lack of representativeness may influence estimates.

Although data on CKD progression is not yet available from the CKiD study, proteinuria represents a risk factor for progression among those with CKD. As study follow-up continues, more data on CKD progression in these patients will be available and progression rates will replace baseline proteinuria as the measure of interest. Mortality as another possible health consequence will be tracked, but rates are expected to be too low to report among children. Another possible pediatric-specific consequence that may be available with further study follow-up is growth rate. Analyses for this measure were restricted to the 419 children enrolled in CKiD with measured iohexol GFR and proteinuria (urine protein/creatinine or Up/c ratio, measured in g/g, thus presented without units) as well as known gender, age, CKD diagnosis and current medication use. Complete methods can be found in Wong et al. (2009)."
FieldData
Description of MeasurePrevalence of proteinuria among children with CKD
Data SourceCKiD prospective observational cohort study
Type of Data SourcePrivate
Data SetCKiD summarized data
Health Care System DataNo
Regional or National?National
Demographic GroupChildren (1-16 years old) with mild to moderate CKD (Schwartz-estimated GFR of 30-90 ml/min/1.73 m²) who are treated throughout 48 pediatric nephrology centers in North America (46 U.S., 2 Canadian centers)
NumeratorEnrolled children with abnormal protein/creatinine (Up/c) ratio and with measured iohexol GFR as well as known gender, age, CKD diagnosis and current medication use
DenominatorEnrolled children with measured iohexol GFR and proteinuria (urine protein/creatinine or Up/c ratio) as well as known gender, age, CKD diagnosis and current medication use
Definition of CKDSchwartz-estimated GFR of 30-90 ml/min/1.73 m² (for entry into study)
Glomerular filtration rateMeasured, by iohexol
ProteinuriaNormal, Up/c<0.2; significant, Up/c 0.2-2; and nephrotic, Up/c>2
Primary Data Source IndicatorUp/c
Primary Indicator Method of MeasurementMeasured at central lab (University of Rochester) from 1st-morning urine samples
Secondary (1) VariableGFR
Secondary (1) Indicator Method of MeasurementMeasured by plasma iohexol disappearance curves (iGFR)
Frequency of Measurement (Primary)At all scheduled visits; only baseline presented
U.S. Region Covered by Primary VariableAll
Period Currently Available2004–2008
Pending DataNone for baseline; further visits scheduled
Additional Data Items of InterestStage of CKD, stratification variables of interest (age, gender, race/ethnicity )
Limitations of IndicatorSome samples may not be 1st morning; not all patients had iGFR measured
Analytical ConsiderationsData summarized by CKiD investigators (see Wong et al.); as with all cohort studies, selection bias and possible confounding
References and Sources:
  • Wong CS, Pierce CB, Cole SR, et al. CKiD Investigators. Association of proteinuria with race, cause of chronic kidney disease, and glomerular filtration rate in the chronic kidney disease in children study. Clin J Am Soc Nephrol. 2009;4(4):812-9.
    http://www.ncbi.nlm.nih.gov/pubmed/19297612
Suggested Citation:
Centers for Disease Control and Prevention. Chronic Kidney Disease Surveillance System—United States.
website. http://www.cdc.gov/ckd