Abstract 072: Newly Developed Personal Device can Detect Changes and Variations of Urinary Na/K Ratio with Standardized Low- and High-salt Meals in Healthy Volunteers
Background: A low-sodium (Na), high-potassium (K) diet is recommended to suppress blood pressure elevation, but determining the absolute amounts of Na and K in a diet is difficult. A novel portable device was developed to allow easy measurement of urinary Na/K ratio on the spot. In this study, our aims were 1): to observe the changes of urinary Na/K ratio in subjects on low- and high-Na diet and 2): to determine if there are differences in urinary Na/K ratio between subjects with and without salt sensitivity.
Methods: Healthy volunteers (14 subjects) ingested standardized low- (3 g NaCl /day) and high-Na (20 g NaCl/day) meals for 7 days each. Urinary Na/K ratio was measured at each voiding using a prototype device (Omron Healthcare). Collection of blood and 24-hour urine was conducted at the end of each diet period (unrestricted (NS), low-salt (LS), and high-salt (HS)). Those with mean blood pressure difference (LS vs. HS) ≥ 5% were determined as salt-sensitive (SS) and others salt-resistant (SR).
Results: Urinary Na/K ratio reached a plateau approximately 3 days after each change in the Na level of the diet. Urinary Na/K ratio of spot urine correlated well with Na/K ratio of 24-hour urine. Average urinary Na/K ratio was 3.9 ± 1.9 on the last day of NS, 0.8 ± 0.3 on LS, and 6.9 ± 2.1 on HS. The variation of urinary Na/K ratio was small during the LS diet period. The change in urinary Na/K ratio of SS group tended to be slower than that of SR. This device may also be useful in diabetic and proteinuric patients as Na/K ratio was affected minimally by experimental glucose and protein addition.
Conclusion: Using an easy-to-use device, measurements of urinary Na/K ratio keenly reflected the sodium level of the diet.
Author Disclosures: J. Yatabe: A. Employment; Significant; Endowed Chairs (MSD, Chugai, Dainippon Sumitomo, Takeda, Teijin Pharma, AstraZeneca, Baxter, Daiichi-Sankyo). M.S. Yatabe: None. K. Takano: None. A. Watanabe: None. S. Kurosawa: None. M. Yonemoto: None. M. Nochi: None. Y. Ikeda: None. T. Iwahori: A. Employment; Significant; Omron Healthcare Co., Ltd. T. Shiga: A. Employment; Significant; Omron Healthcare Co., Ltd.. T. Watanabe: None. J. Kimura: None.
- © 2014 by American Heart Association, Inc.