Objective: The present study aimed to evaluate salt-reduction education using a self-monitoring urinary salt-excretion device.Design: Parallel, randomized trial involving two groups. The following parameters were checked at baseline and endline of the intervention: salt check sheet, eating behaviour questionnaire, 24 h home urine collection, blood pressure before and after urine collection.Setting: The intervention group self-monitored urine salt excretion using a self-measuring device for 4 weeks. In the control group, urine salt excretion was measured, but the individuals were not informed of the result.Subjects: Seventy-eight individuals (control group, n 36; intervention group, n 42) collected two 24 h urine samples from a target population of 123 local resident volunteers. The samples were then analysed.Results: There were no differences in clinical background or related parameters between the two groups. The 24 h urinary Na:K ratio showed a significant decrease in the intervention group (−1·1) compared with the control group (−0·0; P=0·033). Blood pressure did not change in either group. The results of the salt check sheet did not change in the control group but were significantly lower in the intervention group. The score of the eating behaviour questionnaire did not change in the control group, but the intervention group showed a significant increase in eating behaviour stage.Conclusions: Self-monitoring of urinary salt excretion helps to improve 24 h urinary Na:K, salt check sheet scores and stage of eating behaviour. Thus, usage of self-monitoring tools has an educational potential in salt intake reduction.

To prevent and treat hypertension, it is important to restrict salt in one's diet since adolescence. However, an effective salt‐reduction education system has yet to be established. Besides accurate evaluation, we believe that the frequent usage of a measurement device may motivate individuals to avoid high salt intake. The present study evaluated the use of a urinary salt excretion measurement device for salt‐reduction education in a parallel randomized trial of two groups. The sample comprised 100 university students who provided consent to participate. A survey with 24‐hour home urine collection and blood pressure measurement was conducted. Participants in the self‐monitoring group measured their own urinary salt excretion level for 4 weeks, using the self‐measurement device. Analyses were conducted on 51 participants in the control group and 49 in the self‐monitoring group. At baseline, there was no significant difference between the two groups in terms of their characteristics and 24‐hour urinary salt excretion levels. After intervention, 24‐hour urinary sodium/potassium ratio showed no change in the control group [baseline score: 4.1 ± 1.5; endline score: 4.2 ± 2.0; P = 0.723], but it decreased significantly in the self‐monitoring group [baseline score: 4.0 ± 1.7; endline score: 3.5 ± 1.4; P = 0.044]. This change was significant even after adjusting for baseline and endline differences between groups using analysis of covariance (P = 0.045). The self‐monitoring urinary salt excretion measurement device improved the 24‐hour urinary sodium/potassium ratio. The device is a useful and practical tool for educating young individuals about dietary salt reduction.

This study aimed to examine the usefulness of the self-monitoring of urinary salt excretion for educating individuals about the risk of excessive dietary salt intake. The subjects were 30 volunteers (15 men and 15 women) not consuming anti-hypertensive medication. The subjects measured urinary salt excretion at home for 4 weeks using a self-monitoring device. Blood pressure (BP), anthropometric variables and nutritional variables (by a dietary-habits questionnaire) were measured before and after the measurement of urinary salt excretion. Statistical analyses were performed, including paired t-tests, Chi-square test, Pearson’s product moment correlation coefficient and multiple linear regression analysis. In all subjects, the average urinary salt excretion over 4 weeks was 8.05±1.61 g/day and the range (maximum-minimum value) was 5.58±2.15 g/day. Salt excretion decreased significantly in weeks 3 and 4 (P<0.05 and P<0.01, respectively). Diastolic BP decreased from 77.7±14.3 (at baseline) to 74.3±13.3 after 4 weeks (P<0.05), while systolic BP and anthropometric variables remained unchanged. Nutrition surveys indicated that energy intake was correlated with salt intake both before and after the measurements; changes in both variables during the observation period were correlated (r=0.40, P<0.05). The percentage of subjects who were aware of the restriction in dietary salt intake increased from 47 to 90%. In conclusion, daily monitoring of the amount of urinary salt excretion using a self-monitoring device appears to be an effective educational tool for improving the quality of life of healthy adults.