title: Salt loading has a more deleterious effect on flow-mediated dilation in salt-resistant men than women.
abstract: OBJECTIVE
  Dietary sodium loading has been shown to adversely impact endothelial function independently of blood pressure (BP). However, it is unknown whether dietary sodium loading impacts endothelial function differently in men as compared to women. The aim of this study was to test the hypothesis that endothelial-dependent dilation (EDD) would be lower in men as compared to women in response to a high sodium diet.
  
  
  RESULTS
  Thirty subjects (14F, 31±2y; 16M, 29±2y) underwent a randomized, crossover, controlled diet study consisting of 7 days of low sodium (LS; 20 mmol/day) and 7 days of high sodium (HS; 300-350 mmol/day). Salt-resistance was determined by a change in 24-hr mean arterial pressure (MAP) ≤ 5 mm Hg between HS and LS as assessed on day 7 of each diet. Blood and 24-hr urine were also collected and EDD was assessed by brachial artery flow-mediated dilation (FMD). By design, MAP was not different between LS and HS conditions and urinary sodium excretion increased on HS diet (P < 0.01). FMD did not differ between men and women on the LS diet (10.2 ± 0.65 vs. 10.7 ± 0.83; P > 0.05) and declined in both men and women on HS (P < 0.001). However, FMD was lower in men as compared to women on HS (5.7 ± 0.5 vs. 8.6 ± 0.86; P < 0.01).
  
  
  CONCLUSIONS
  HS reduced FMD in both men and women. In response to an HS diet, FMD was lower in men compared to women suggesting a greater sensitivity of the vasculature to high sodium in men.
authors.affiliation: Department of Behavioral Health and Nutrition, University of Delaware, Newark, DE, USA; Department of Kinesiology and Applied Physiology, University of Delaware, Newark, DE, USA. Electronic address: slennon@udel.edu.
authors.forename: S
authors.initials: S
authors.lastname: Lennon-Edwards
authors.affiliation: Department of Kinesiology and Applied Physiology, University of Delaware, Newark, DE, USA.
authors.forename: M G
authors.initials: MG
authors.lastname: Ramick
authors.affiliation: Department of Kinesiology and Applied Physiology, University of Delaware, Newark, DE, USA.
authors.forename: E L
authors.initials: EL
authors.lastname: Matthews
authors.affiliation: Department of Kinesiology and Applied Physiology, University of Delaware, Newark, DE, USA.
authors.forename: M S
authors.initials: MS
authors.lastname: Brian
authors.affiliation: Department of Kinesiology and Applied Physiology, University of Delaware, Newark, DE, USA; Department of Biological Sciences, University of Delaware, Newark, DE, USA.
authors.forename: W B
authors.initials: WB
authors.lastname: Farquhar
authors.affiliation: Department of Kinesiology and Applied Physiology, University of Delaware, Newark, DE, USA; Department of Biological Sciences, University of Delaware, Newark, DE, USA.
authors.forename: D G
authors.initials: DG
authors.lastname: Edwards
mesh_terms: D000328:Adult; D001794:Blood Pressure / Q000187:drug effects*; D015992:Body Mass Index; D001916:Brachial Artery / Q000187:drug effects / Q000503:physiopathology; D018592:Cross-Over Studies; D004039:Diet, Sodium-Restricted; D005260:Female; D064368:Healthy Volunteers; D006801:Humans; D008297:Male; D017419:Potassium, Dietary / Q000008:administration & dosage / Q000097:blood; D012737:Sex Factors; D012982:Sodium, Dietary / Q000008:administration & dosage / Q000009:adverse effects* / Q000097:blood; D055815:Young Adult
chemical_list: D017419:Potassium, Dietary; D012982:Sodium, Dietary
keywords: Flow-mediated dilation; Sex; Sodium