Associations Between Salt-Restriction Spoons and Long-Term Changes in Urinary Na/K Ratios and Blood Pressure: Findings From a Population-Based Cohort.

Background There have been few studies on the relationship between long-term changes in sodium intake and blood pressure. A method of reducing sodium intake in a population that is known for high-sodium intake based on homemade cooking is also needed. Methods and Results Our study was based on a baseline survey of 15 350 individuals aged 18 to 69 years with multistage random sampling and a 3-year salt-restriction campaign across Shandong Province, China. We included 339 individuals from six districts/counties in this cohort study, and the 24-hour urinary sodium-potassium ratio (Na/K) served as an indicator of sodium intake. The average change in ratio was 2.39 (95% CI, 2.17-2.61) from 6.81 (95% CI, 6.41-7.21) at baseline to 4.41 (95% CI, 4.18-4.64) during the resurvey. Following a reduction from low to high quartiles of urinary Na/K ratio, the average increases were 10.9 (95% CI, 8.9-12.9), 9.2 (95% CI, 6.9-11.5), 6.3 (95% CI, 4.0-8.6), and 5.3 (95% CI, 2.9-7.7) mm Hg for systolic blood pressure ( for trend=0.019) and 3.8 (95% CI, 2.4-5.2), 2.9 (95% CI, 1.7-4.2), 1.6 (95% CI, 0.4-2.8), and -0.3 (95% CI, -1.4-0.8) mm Hg for diastolic blood pressure ( for trend=0.002), respectively. A reduction in salt intake was evident for people using a 2-g salt-restriction spoon for cooking (-3.49 versus -2.22; =0.027) after adjustment of confounding factors, compared with nonusers. Similar findings were obtained for other salt-restriction spoon-based indicators. Conclusions Our study indicated that using a salt-restriction spoon for cooking was associated with reduced salt intake that led to a blunting of blood pressure deterioration. This finding further supports the salt-restriction spoon-based strategy for people whose primary salt intake is from homemade cooking.