Relationship between the behavior change model and salt intake in hypertensive patients: a single non-specialized hypertension clinic prospective observational study

We investigated whether changes in salt reduction readiness are associated with changes in estimated daily salt intake and blood pressure (BP). We divided 86 hypertensive patients into groups with high and low readiness for salt-reducing behavior [an up (UP) and a down (DN) groups, respectively] based on the transtheoretical model (TTM) over a 12-month observation period. We then investigated the relationships between changes in the TTM stage and changes in daily salt intake and BP over 12 months. The patients in the UP group had significantly increased urine potassium concentrations (from 51.2 ± 23.3 mEq/L at baseline to 56.9 ± 25.5 mEq/L at 12 months; P = 0.048) and significantly decreased estimated 24-h urinary salt excretion (from 9.7 ± 2.9 g/day at baseline to 8.4 ± 2.8 g/day at 12 months; P = 0.045). In addition, they also had significantly lower changes in urine sodium concentration (−13.1 ± 46.1 vs. −6.6 ± 59.7 mEq/L; P = 0.048), significantly increased changes in urine potassium concentration (5.7 ± 20.1 vs. −4.8 ± 28.6 mEq/L; P = 0.030), and significantly decreased changes in estimated 24-h urinary salt excretion (−1.3 ± 2.6 vs. −0.1 ± 2.6 g/day; P = 0.045) compared with patients in the DN group. However, their home BP did not improve over 12 months. The hypertensive patients who increased their readiness or maintained a high readiness for salt reduction over 12 months showed a significant increase in daily potassium intake and significant decrease in daily salt intake.