Evaluation of the individual effects of a health education program for sodium restriction by a simple method for measuring 24-hour urinary sodium excretion.

Abstract

A simple method for measuring 24-hr urinary sodium excretion was applied to the evaluation of the individual effects of a health education program for sodium restriction in a rural community in Japan. Eighteen subjects (6 males and 12 females) between 35 and 72 years of age were advised to reduce their sodium intake. Twentyfour-hour urinary sodium, potassium excretion, and sodium/potassium ratio were measured using the simple method for seven consecutive days in three periods which were before the sodium restriction, 6 months after the sodium restriction, and 6 months after the end of the program. Mean sodium excretion of 18 subjects significantly decreased (p <0.05) after the end of the program. The reduced level was maintained until six months after the end of the program. Within individual cases, sodium excretion decreased significantly in subjects who had levels higher than 170 mmol at the initial stage. The reduced levels of sodium excretion were maintained until six months after the end of the program except for one subject. The subjects who had an initial level lower than 170 mmol of sodium, which is the upper limit of present recommendation for Japanese adults, did not change their levels, sodium ; potassium ; urinary excretion ; intervention ; epidemiologic methods Epidemiological (Kesteloot et al. 1987; Intersalt Cooperative Research Group 1988;) and experimental studies (Dahl et al. 1972) have suggested that excessive sodium intake is associated with elevated blood pressure. Recent studies suggest that dietary intervention trials in individuals are effective in lowering blood pressure in hypertensive patients (Beard et al.