Estimated 24-hour urinary sodium excretion and sodium-to-potassium ratio among Japanese elementary school teachers and school lunch cooks.

Background:Dietary salt intake is largely responsible for increase in blood pressure that is commonly seen with aging. In our previous study carried out in 2015, we calculated the 24-hour urinary sodium excretion and sodium-to-potassium (Na/K) ratio among elementary school children. In the present study, we aimed to examine the same items among the school children's teachers and lunch cooks.Methods:Of 153 recruited participants, urine samples were collected from 129 subjects (84.3%), and 124 subjects (81.0%; 37 male teachers, 65 female teachers, and 22 female cooks) whose dietary habits were confirmed were included in the final study analysis.Results: The median estimated 24-hour urinary salt excretion (g/day) was 8.2 in male teachers, 7.4 in female teachers, and 8.9 in cooks. The median urinary Na/K ratio (mEq/mEq) was 4.1 in male teachers, 3.6 in female teachers, and 4.0 in cooks. In both male and female teachers and cooks, no association was found between urinary salt excretion or urinary Na/K ratio and an awareness of the need to restrict salt intake. The proportion of subjects with both a urinary salt excretion and Na/K ratio above the median was high in male teachers and cooks, whereas the proportion of subjects who scored below the median in both tests was high in female teachers.Conclusion:It should be considered that elementary school teachers and cooks who have been provided with the results of their own salt excretion could realize the importance of reducing salt consumption from early childhood and the continuous salt intake reduction education for children.

Characteristic dietary habits associated with high values of estimated 24-hours urinary sodium excretion and sodium-to-potassium ratio assessed by age group among the residents of a rural town in Japan.

Excess salt intake causes hypertension and cardiovascular disease (CVD). We examined estimated 24-h urinary sodium (Na) excretion and sodium-to-potassium (Na/K) ratio and analyzed the association between estimated 24-h urinary salt excretion (urinary salt excretion) and dietary habits by age group to develop effective public health programs to promote salt reduction. A total of 4,051 subjects aged 30-74 years old received information during periodic health checkups. In the analysis, 1,202 subjects without hypertension whose urine samples and dietary habits were confirmed (29.7%; 483 men and 719 women) were included. The median urinary salt excretion was 9.1 g/day in men and 8.6 g/day in women. Daily intake of soups in men aged <50 years old and daily intake of beans, soups, or pickles in women aged ≥70 years old were associated with high values of urinary salt excretion (p = .03, p < .01, p = .01, and p = .02, respectively). The median urinary Na/K ratio (mEq/mEq) was 4.4 in both men and women. Daily intake of vegetables in men aged <50 years old and more than 3 days/week intake of fruit in women aged 50-59 and 60-69 years old were associated with lower values of urinary Na/K ratio (p = .03, p < .01, and p < .01, respectively). These findings revealed that dietary salt reduction should be promoted according to age group with regard to differences in dietary habits associated with high values of estimated 24-h urinary Na excretion and urinary Na/K ratio.

Estimation of salt intake and sodium-to-potassium ratios assessed by urinary excretion among Japanese elementary school children.

Dietary salt intake is largely responsible for the increase in blood pressure with age. It is important to start effective prevention approaches during childhood. In this study, we estimated salt intake and sodium-to-potassium (Na/K) ratios assessed by urinary excretion among elementary school children in Kyoto, Japan. A total of 331 subjects aged 9-11 years participated in school checkups in April 2015. Urinary concentrations of sodium, potassium, and creatinine were measured in first morning urine samples. The subjects' dietary habits were confirmed by questionnaires completed by their parents. The median estimated urinary sodium excretion was 129.0 mmol/day (5.7g/day of salt). In 30.2% of the subjects, their estimated salt intake exceeded their age-specific dietary goal for salt intake recommended by the Dietary Reference Intakes for Japanese 2015. Multivariate linear regression model analysis after adjustment for age revealed a significant positive correlation between seaweeds or fish paste products consumption and the estimated salt intake (p = 0.02 and 0.02, respectively). The median urinary Na/K ratio (mEq/mEq) was 4.5. Multivariate linear regression model analysis revealed a significant negative correlation between fruit consumption and urinary Na/K ratio (p = 0.04). These results suggest that the high sodium intake and the high Na/K ratios occur among Japanese elementary school children, and that the urinary Na/K ratio in children may be reduced by the daily consumption of fruit.