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 &lt;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 (<i>p</i> = .03, <i>p</i> &lt; .01, <i>p</i> = .01, and <i>p</i> = .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 &lt;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 (<i>p</i> = .03, <i>p</i> &lt; .01, and <i>p</i> &lt; .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.