Stages of change for salt intake and urinary salt excretion: Baseline results from the High-Risk and Population Strategy for Occupational Health Promotion (HIPOP-OHP) study

We investigate the relationship of urinary salt excretion to the stage of change to decrease salt intake in the Japanese diet. The data reported here were obtained from a baseline survey of the High-Risk and Population Strategy for Occupational Health Promotion (HIPOP-OHP) study that was conducted as a non-randomized control trial at 12 worksites in Japan. A total of 6,816 subjects (5,410 male, 1,406 female) were used in 1999 and 2000 for the analysis. We used three categories of stage of change: precontemplation or contemplation (P/C), preparation (P), and action or maintenance (A/M). Urinary salt excretion was estimated from the sodium and creatinine concentrations in spot urine samples. Multivariate analysis indicated that urinary salt excretion among males was 0.3 g/day greater in the P/C stage than in the A/M stage (p<0.05). For non-obese females, urinary salt excretion in the P/C stage was 0.6 g/day greater than in the A/M stage (p<0.05). Multivariate analysis showed that diastolic blood pressure in males not taking antihypertensive agents was 1.3 mmHg lower in the P/C stage than in the A/M stage (p<0.05). A similar but statistically insignificant tendency was observed among non-obese females. A significant association was demonstrated between stage of change for dietary salt intake and urinary salt excretion for both males and non-obese females. There may be a potential application of the stage of change model for reducing dietary salt intake in a health promotion program.