Abstract P332: Dietary Salt Intake and Blood Pressure Control in Hypertensive Individuals Under Antihypertensive Treatment During 7 Years

Purpose: Excess salt intake is one of the most important causes of hypertension. Salt restriction is a key strategy in the management of hypertension and, thus, should be instructed for hypertensive patients under medical treatment. We investigated recent changes in dietary salt intake and blood pressure (BP) levels in hypertensive patients. Methods: Total of 12422 hypertensive subjects (male 71.0% [8814 of 12422], 64.6±9.2 year-old) under medical treatment who visited our hospital for a physical checkup from 2010 to 2016 were enrolled. They were divided into 3 groups according to the number of antihypertensive drugs prescribed (1, 2 and ≥3 drugs). Cross-sectional analyses were performed using data in each year and changes during the 7 years were investigated. Individual salt intake was estimated using a spot urine by a previously reported method. Results: BP levels and the accomplishment rate of the target BP (<140/90mmHg) were improved in each group during the 7 years without significant difference among the groups (Overall 2010 to 2016; BP 132.7±13.6/80.0±8.9 to 128.8±13.7/76.3±9.6 mmHg and accomplishment ratio 65.6 [968 of 1475] to 76.4% [1433 of 1875]). However, individual salt intake was gradually increased in all groups (2010 to 2016 in 1, 2, and ≥3 drugs; 11.7±3.7 to 12.2±4.0, 11.9±3.7 to 12.7±3.9, and 12.2±3.9 to 12.9±4.1 g/day, respectively) and the accomplishment rate of salt restriction (<6g/day) was significantly reduced in subjects with increased number of antihypertensive drugs (3.5 [225 of 6435], 2.8 [125 of 4564], and 2.3% [33 of 1423] in groups with 1, 2, and ≥3 drugs, respectively). The accomplishment rate of the target BP was significantly higher in patients who achieved salt restriction than in those who did not achieve salt restriction in all groups (Over all; 80.2 [307 of 383] vs. 73.3% [8829 of 12039]). Conclusions: The control of BP in individuals with antihypertensive medications was improved in the last 7 years. However, salt restriction has not been successfully achieved especially in hypertensive patients with multiple antihypertensive medications. Excess salt intake may induce resistance to antihypertensive treatment and, thus, increases the number of antihypertensive drugs for BP control.