Six random specimens of daytime casual urine on different days are sufficient to estimate daily sodium/potassium ratio in comparison to 7-day 24-h urine collections

Toshiyuki Iwahori, Hirotsugu Ueshima, Naoko Miyagawa, Naoto Ohgami, Hideyuki Yamashita, Takayoshi Ohkubo, Yoshitaka Murakami, Toshikazu Shiga, Katsuyuki Miura

Research output: Contribution to journalArticlepeer-review

43 Citations (Scopus)

Abstract

The objective of this study was to determine the optimal number and type of casual (spot) urine specimens required to estimate an individual's urinary sodium/potassium (Na/K) ratio. A total of 48 participants, 25 men and 23 women, aged between 25 and 59 years, was recruited from healthy volunteers. The Na/K ratio in each casual urine and 7-day 24-h urine sample was measured. Correlation analysis and the quality of agreement by the Bland and Altman method between casual urine and 24-h urine were analyzed. The mean Na/K ratio of 7-day 24-h urine was 4.3. The mean Na/K ratio of six random specimens of daytime (collected between 09 and 17 hours) casual urine correlated most strongly with the Na/K ratio of 7-day 24-h urine (r=0.87). The bias for the mean Na/K ratio between 7-day 24-h urine and daytime casual urine was almost negligible (0.03), and the quality of agreement for the mean of the six random, daytime casual urine specimens on different days was similar to that of the 2-day 24-h urine samples for estimating 7-day 24-h values. Our findings show that the mean Na/K ratio of six random daytime casual urine specimens on different days was a good substitute for the 2-day 24-h urine Na/K ratio.

Original languageEnglish
Pages (from-to)765-771
Number of pages7
JournalHypertension Research
Volume37
Issue number8
DOIs
Publication statusPublished - 2014 Aug
Externally publishedYes

Keywords

  • education of patients
  • potassium
  • salt
  • sodium
  • urine specimen collection

ASJC Scopus subject areas

  • Internal Medicine
  • Physiology
  • Cardiology and Cardiovascular Medicine

Fingerprint

Dive into the research topics of 'Six random specimens of daytime casual urine on different days are sufficient to estimate daily sodium/potassium ratio in comparison to 7-day 24-h urine collections'. Together they form a unique fingerprint.

Cite this