title: High dietary sodium intake impairs endothelium-dependent dilation in healthy salt-resistant humans.
abstract: BACKGROUND
  Excess dietary sodium has been linked to the development of hypertension and other cardiovascular diseases. In humans, the effects of sodium consumption on endothelial function have not been separated from the effects on blood pressure. The present study was designed to determine if dietary sodium intake affected endothelium-dependent dilation (EDD) independently of changes in blood pressure.
  
  
  METHODS
  Fourteen healthy salt-resistant adults were studied (9M, 5F; age 33 ± 2.4 years) in a controlled feeding study. After a baseline run-in diet, participants were randomized to a 7-day high-sodium (300-350 mmol/day) and 7-day low-sodium (20 mmol/day) diet. Salt resistance, defined as a 5 mmHg or less change in a 24-h mean arterial pressure, was individually assessed while on the low-sodium and high-sodium diets and confirmed in the participants undergoing study (low-sodium: 85 ± 1 mmHg; high-sodium: 85 ± 2 mmHg). EDD was determined in each participant via brachial artery flow-mediated dilation on the last day of each diet.
  
  
  RESULTS
  Sodium excretion increased during the high-sodium diet (P < 0.01). EDD was reduced on the high-sodium diet (low: 10.3 ± 0.9%, high: 7.3 ± 0.7%; P < 0.05). The high-sodium diet significantly suppressed plasma renin activity (PRA), plasma angiotensin II, and aldosterone (P < 0.05).
  
  
  CONCLUSIONS
  These data demonstrate that excess salt intake in humans impairs endothelium-dependent dilation independently of changes in blood pressure.
authors.affiliation: Department of Kinesiology and Applied Physiology, University of Delaware, Newark, Delaware, USA.
authors.forename: Jennifer J
authors.initials: JJ
authors.lastname: DuPont
authors.forename: Jody L
authors.initials: JL
authors.lastname: Greaney
authors.forename: Megan M
authors.initials: MM
authors.lastname: Wenner
authors.forename: Shannon L
authors.initials: SL
authors.lastname: Lennon-Edwards
authors.forename: Paul W
authors.initials: PW
authors.lastname: Sanders
authors.forename: William B
authors.initials: WB
authors.lastname: Farquhar
authors.forename: David G
authors.initials: DG
authors.lastname: Edwards
mesh_terms: D000328:Adult; D004730:Endothelium, Vascular / Q000503:physiopathology*; D005260:Female; D006801:Humans; D008297:Male; D012964:Sodium / Q000008:administration & dosage*; D014664:Vasodilation / Q000502:physiology*
chemical_list: D012964:Sodium