Abstract P402: A New Oral Salt Tolerance Test has Acceptable Consistency for its First Volunteer

Objectives: One of the cores of salt restriction is to keep balance of salt intake and excretion. There is still no method to identify salt tolerance based on salt intake and excretion. In order to evaluate the ability to absorb and excrete salt, we established a new method Oral Salt Tolerance Test (OSTT). We firstly evaluated its consistency for one person among repeated tests. Methods: After signing informed consent, the 40-year-old healthy woman volunteer was asked to keep fasting after 9PM and empty bladder before sleep on the day before test. On the morning for test, she emptied bladder firstly and then drank 500ml 0.9% saline in 15 minutes. Urine volume and urine samples for sodium test were collected at 30min, 60min, 120min and 180min time points. This test was repeated twice on the other two days. Results: 1. According to sodium concentration and urine volume at each timepoints, we calculated equal sodium chloride amount. The baseline urine sodium concentration before test 1 is higher than those before test 2 and test 3. Accordingly, the 30min sodium concentration and urine volume are lower and higher respectively than those of the other two tests, while the 30min equal sodium chloride amounts are similar among the three tests. 2. The Intraclass Correlation Coefficient for equal sodium chloride amount among the three tests is 0.94 (95% Confidence Interval 0.6810 to 0.9958) and this indicates that the consistency among the three tests is acceptable. Conclusion: The acceptable consistency makes this new OSTT possible to screen more subjects with various clinical conditions. In the future, we hope this new method would give us a novel insight for hypertension or renal diseases patients.