Variability in 24-hour urine sodium excretion in children

Kiang Liu*, Richard Cooper, Ivan Soltero, Jeremiah Stamler

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

51 Scopus citations


How many 24-hour urine sodium measurements are adequate for characterizing a child's salt intake? Can overnight urine specimens accurately replace 24-hour collections for salt assessment? A sample of 73 6tb-8th grade children was taken from two parochial schools in Chicago to inrestigate systematically these questions. Seven consecutive 24-hour-urine specimens were collected from each child. The estimated ratio of intra- to inter-individual variances was 1.94 for 24-hour-urine sodium. Based on this value, eight 24-hour specimens are necessary to limit to 10% the diminution of the estimated correlation coefficient between 24- hour-urine sodium and blood pressure. Six measurements are required to reduce to 0.01 the probability of misclassifying a child in tertile 1 versus fertile 3. The overnight specimens show a moderate consistency with the 24-hour collections in detecting children with high or low salt intake. For example 92% and 85% of children in the fifth quintile and the third tertile respectively of the true mean overnight sodium hare their true mean 24-hour Na In the upper half of the distribution. These results suggest that in a large scale epidemiologic study, overnight specimens may be reasonable alternatives when 24-hour-urine sodium is practically very difficult to collect.

Original languageEnglish (US)
Pages (from-to)631-636
Number of pages6
Issue number6
StatePublished - Nov 1979


  • Children
  • Sodium excretion
  • Urine sample

ASJC Scopus subject areas

  • Internal Medicine


Dive into the research topics of 'Variability in 24-hour urine sodium excretion in children'. Together they form a unique fingerprint.

Cite this