PLoS ONE (Jan 2021)

Diagnostic usefulness of the spot urine sodium/potassium ratio in cirrhotic patients with ascites.

  • Jin Wook Lee,
  • Jae Seok Hwang,
  • Woo Jin Chung,
  • Heon Ju Lee,
  • Jung Gil Park,
  • Chang Hyeong Lee,
  • Byung Seok Kim,
  • Jeong Eun Song,
  • Young Oh Kweon,
  • Won Young Tak,
  • Soo Young Park,
  • Se Young Jang,
  • Jeong Ill Suh,
  • Byoung Kuk Jang

DOI
https://doi.org/10.1371/journal.pone.0253886
Journal volume & issue
Vol. 16, no. 6
p. e0253886

Abstract

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Background and aimsThe low-salt diet is considered important for control of ascites in cirrhotic patients. To validate whether the spot urine sodium (Na)/potassium (K) ratio could replace 24-h urine Na (uNa) excretion in assessing low-salt diet compliance.MethodsWe prospectively studied 175 patients. 24-h urine collection and spot urine collection were performed. Subsequently, 24-h uNa, urine creatinine (uCr), and spot urine Na and K were assessed. A complete urine collection was confirmed based on 24-h uCr excretion levels of 15mg/kg/day for men and 10mg/kg/day for women. The area under the receiver operating characteristic (AUROC) curve analysis was performed to evaluate the feasibility of spot urine Na/K ratio in predicting 24-h uNa greater than 78mmol/day.ResultsOut of 175 patients, 24-h urine samples were completely collected in 57 patients only. Moreover, urine samples were not completely collected in 118 patients because their 24-h uCr excretion level was less than the established criteria. In complete urine collection group, AUROC curve for spot urine Na/K ratio in predicting 24-h uNa greater than 78mmol/day was 0.874±0.051 (PConclusionsThe spot urine Na/K ratio reflects 24-h uNa, but the AUROC value obtained in this study is lower than that of a previous study. Considered the large number of patients with incomplete urine collection, validating 24-h complete urine collection criteria is necessary.