Practical use and target value of urine sodium-to-potassium ratio in assessment of hypertension risk for Japanese: Consensus Statement by the Japanese Society of Hypertension Working Group on Urine Sodium-to-Potassium Ratio

Epidemiological studies have demonstrated that the urine sodium-to-potassium (Na/K) ratio is more positively associated with high blood pressure and cardiovascular disease risk than either urine sodium or potassium excretion alone. In this consensus statement, we recommend using the average Na/K ratio of casual urines randomly taken in various times on at least four days a week for a reliable individual estimate because of high day-to-day and intraday variability of casual urine Na/K ratio within individuals. Although a continuous positive association exists between the Na/K ratio and high blood pressure or cardiovascular disease risk, for clinical and public health decision making for Japanese, we recommend using an average urine Na/K ratio of 2 as an optimal target value because this aligns with recommendations for both sodium and potassium intake in the Dietary Reference Intakes for Japanese, 2020, considering a typical Japanese dietary pattern. We also suggest that an average urine Na/K ratio of 4 is a feasible target value to achieve a temporary goal of being below the mean values of the urine Na/K ratio across Japanese general populations. These recommendations apply mainly for apparently healthy individuals, but not for patients with specific conditions due to the lack of supporting data. Current evidence for the usefulness of measuring the urine Na/K ratio for the prevention or control of hypertension remains inconclusive and warrants further investigation.