Abstract

This study was carried out in order to examine the urinary excretion of electrolytes (Na, K) and their relationship with blood pressure, and to estimate the amount of daily salt intake in a rural community. From January to March in 1987, a mobile screening team visited 40 villages, and carried out health screening of 537 adult volunteers whose age were over 30 years and collected 12-hours overnight urine. To determine the completeness of collection, the urinary creatinine was measured. If the creatinine excretion was beyond the range given to the age group, the sample was excluded from the analysis as an imcomplete collection; 345 samples were remained for analysis. This study revealed the following results. 1. The mean excretion amounts of urinary electrolytes for 12 hours were Na 193.5 mEq, K 20.8 mEq, creatinine 1.0 g. The mean ratio of electrolytes were Na/K 9.84, Na/creatinine 0.44, K/creatinine 0.046. 2. Both the mean excretion amount of K and the mean ratio of K/creatinine were less in hypertensives than in normotensives. K excretion also showed a tendency towards a decrease in inverse proportion to systolic blood pressure when it exceeded 120 mmHg. There was no significant difference between the hypertensives and normotensives in Na excretion. The sodium to potassium ratio increased in proportion to systolic blood pressure. 3. The meand daily salt excretion amount was 22.4 g. Assuming that 90% of the intake was excreted, the estimated amount of daily salt intake was 24.9 g.

• Keywords: electrolyte excretionhypertensionsalt intake