Long-term compliance of salt restriction and blood pressure control status in hypertensive outpatients

The purpose of the present study was to investigate the long-term compliance with salt restriction and blood pressure (BP) control status in Japanese hypertensive outpatients. Subjects included 103 patients, 59 women and 44 men, mean age 67 +/- 9 years, who underwent successful 24-h home urine collection more than 10 times over an interval of 5 years. Urinary salt, potassium, and creatinine were measured. During the follow-up period (average 8.6 years), participants underwent urine collection 11.4 times in average. Urinary salt excretion at the last visit was significantly lower than that of the first visit (8.2 +/- 3.1 vs. 9.6 +/- 3.7 g/day; p < 0.01). The achievement of urinary salt excretion <6 g/day increased from 18.5% at the first visit to 26.2% at the last visit. Similarly, BP at the last visit was significantly lower than that of the first visit (130 +/- 14/69 +/- 11 vs. 145 +/- 17/86 +/- 12 mmHg; p < 0.01). The achievement rate of BP <140/90 mmHg and <130/85 mmHg also increased significantly during this period (39.2% to 70.8% and 13.7% to 39.6%, respectively, p < 0.01). Results suggest that urinary salt excretion decreased by repeated measurements using 24-h home urine collection. Lifestyle modification including weight loss as well as the intensive antihypertensive treatment contributed to the improved BP control during this period.