Journal of Korean Medical Science  2014;29(Suppl 2):S97-S102

doi:10.3346/jkms.2014.29.S2.S97

Estimating 24-Hour Urine Sodium Level with Spot Urine Sodium and Creatinine.

Ho Seok KOO 1 ; Yong Chul KIM ; Shin Young AHN ; Se Won OH ; Suhnggwon KIM ; Ho Jun CHIN ; Jung Hwan PARK

Affiliations

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Keywords

24-hr Urine Sodium; Spot Urine Sodium; Spot Urine Creatinine

Country

Republic of Korea

Language

English

Abstract

The 24-hr urine sodium excretion level was estimated based on the spot urine sodium, and the efficacy of the formula was validated to determine the status of low salt intake <100 mEq Na/day. The 24-hr urine samples were collected from 400 patients. The 24-hr urine creatinine level was estimated with the use of three formulas: a newly derived Korean equation (E24UCR_K), and Tanaka (E24UCR_T) and Cockcroft-Gault (E24UCR_CG) equations. The correlation coefficients between the estimated and measured 24-hr urine creatinine for these three equations were 0.863, 0.846, and 0.896, respectively (All P<0.001). After estimating the 24-hr urine sodium levels, the correlation coefficients between the estimated and measured 24-hr urine sodium levels were 0.466, 0.490, and 0.516, respectively (All P<0.001). The sensitivity of three formulas to estimate the measured 24-hr urine sodium> or =100 mEq/day using the estimated amount> or =100 mEq/day was 84.3%, 87.6%, and 84.8%, respectively. In conclusion, the three equations used to estimate the 24-hr urine sodium content were useful to determine the status of low salt intake.