Increased blood pressure is secondary to intravascular fluid retention, vascular resistance
FRIDAY, Sept. 19 (HealthDay News) -- In patients with resistant hypertension, a high-salt diet increases blood pressure secondary to intravascular fluid retention and impairment of vascular function, according to research presented at the American Heart Association's 62nd High Blood Pressure Research conference held Sept. 17 to 20 in Atlanta.
Eduardo Pimenta, M.D., of the University of Alabama in Birmingham, and colleagues studied 13 patients who were taking an average of 3.6 medications and had a mean office blood pressure of 147.9/85.2 mm Hg. The researchers conducted a randomized, crossover study to evaluate the effects of a high-sodium or low-sodium diet for seven days each separated by a two-week washout.
Compared to the high-sodium diet, the researchers found that the low-sodium diet was associated with significantly lower urinary sodium excretion, and average decreases of 22.6 mm Hg in systolic blood pressure and 9.2 mm Hg in diastolic blood pressure. The investigators also found the low-sodium diet was associated with significant decreases in body weight, brain natriuretic peptide and thoracic fluid content, and an improved pulse wave velocity and aortic augmentation index.
"These results indicate that excessive dietary salt ingestion contributes importantly to the development of resistant hypertension," the authors conclude."