title: Sodium chloride raises blood pressure in normotensive subjects. The study of sodium and blood pressure.
abstract: The effects of dietary sodium on blood pressure in normotensive adults is not well characterized. The Study of Sodium and Blood Pressure (SNaP) is a randomized, double-blind crossover trial using a placebo or 96 meq sodium in 4-week treatment periods separated by a 2-week washout period. Before capsule treatment periods, participants were instructed in a low sodium diet for 10 weeks to reduce urinary sodium excretion to less than 35 meq/8 hr. The low sodium diet was continued throughout the capsule treatment periods. Participants (n = 48; 47 white, 1 black) were 79% male and had an average age of 52 years, a body mass index of 27.6, and a baseline blood pressure of 131/84 mm Hg. Baseline overnight urinary sodium excretion was 51 meq/8 hr and 19 meq/8 hr after the low sodium diet run-in period, before the capsule treatment periods began. Resting, seated blood pressure was measured twice at each visit in a standard fashion. Differences between sodium and placebo treatment periods were as follows: systolic blood pressure, 123.9 versus 120.3 mm Hg, respectively (p less than 0.001); diastolic blood pressure, 78.7 versus 76.4 mm Hg, respectively (p = 0.005); and sodium excretion, 51.3 versus 30.9 meq/8 hr, respectively (p less than 0.001). Both systolic and diastolic blood pressures increased significant amounts in normotensive adults on a low sodium diet supplemented with 96 meq/day sodium. Long-term effects and dose-response relations need further study.
authors.affiliation: Division of Epidemiology, School of Public Health, University of Minnesota, Minneapolis, Minn 55455.
authors.forename: S
authors.initials: S
authors.lastname: Mascioli
authors.forename: R
authors.initials: R
authors.lastname: Grimm
authors.forename: C
authors.initials: C
authors.lastname: Launer
authors.forename: K
authors.initials: K
authors.lastname: Svendsen
authors.forename: J
authors.initials: J
authors.lastname: Flack
authors.forename: N
authors.initials: N
authors.lastname: Gonzalez
authors.forename: P
authors.initials: P
authors.lastname: Elmer
authors.forename: J
authors.initials: J
authors.lastname: Neaton
mesh_terms: D000328:Adult; D001794:Blood Pressure / Q000187:drug effects*; D003971:Diastole; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009318:Natriuresis; D012016:Reference Values; D012965:Sodium Chloride / Q000494:pharmacology*; D013599:Systole
chemical_list: D012965:Sodium Chloride