Low-Sodium DASH reduces oxidative stress and improves vascular function in salt-sensitive humans

J Hum Hypertens. 2009 Dec;23(12):826-35. doi: 10.1038/jhh.2009.32. Epub 2009 Apr 30.

Abstract

Salt induces oxidative stress in salt-sensitive (SS) animals and man. It is not known whether in SS subjects the low-sodium dietary approaches to stop hypertension (LS-DASH) reduces oxidative stress more than DASH, which is high in antioxidants. To assess the effects of DASH and LS-DASH on oxidative stress, 19 volunteers were studied after 3 weeks of a standardized usual low fruits and vegetables diet (ULFV), followed by 3 weeks on DASH (both diets approximately 120 mmol Na(+) per day), then 3 weeks on LS-DASH (60 mmol Na(+) per day). SS was defined as systolic blood pressure >or=5 mm Hg lower on LS-DASH than DASH. In SS subjects (N=9), systolic blood pressure was lower on LS-DASH (111.0+/-2.0 mm Hg) than DASH (118.0+/-2.2, P<0.01) and ULFV (122.3+/-2.7, P=0.002). In salt-resistant (SR) volunteers (N=10), systolic blood pressure was lower on DASH (113.0+/-1.6) than ULFV (119.0+/-1.8, P<0.05) but not LS-DASH (115.7+/-1.8). Urine F2-isoprostanes, a marker of oxidative stress, were lower in SS subjects on LS-DASH (1.69+/-0.24) than ULFV (3.09+/-0.50, P<0.05) and marginally lower than DASH (2.46+/-0.44, P<0.20). F2-isoprostanes were not different among the three diets in SR volunteers (2.18+/-0.29, 2.06+/-0.29, 2.27+/-0.53, respectively). Aortic augmentation index, a measure of vascular stiffness, was lower in SS subjects on LS-DASH than either DASH or ULFV, and lower on DASH than ULFV in SR volunteers. In SS but not SR subjects, LS-DASH is associated with lower values for F2-isoprostanes and the aortic augmentation index. The results suggest that LS-DASH decreases oxidative stress, improves vascular function and lowers blood pressure in SS but not SR volunteers.

Publication types

  • Clinical Trial
  • Research Support, N.I.H., Extramural

MeSH terms

  • Adult
  • Aldosterone / blood
  • Aorta / physiology
  • Blood Pressure / drug effects
  • Cardiac Output / drug effects
  • Diet, Sodium-Restricted*
  • Elasticity
  • Electrolytes / urine
  • F2-Isoprostanes / urine
  • Female
  • Heart Rate / drug effects
  • Humans
  • Hypertension / diet therapy*
  • Hypertension / drug therapy*
  • Insulin / blood
  • Lipids / blood
  • Male
  • Middle Aged
  • Oxidative Stress / drug effects*
  • Phenols / administration & dosage*
  • Plant Extracts / administration & dosage*
  • Potassium Chloride / administration & dosage*
  • Renin / blood
  • Sodium Chloride / administration & dosage
  • Vascular Resistance / drug effects
  • Young Adult

Substances

  • Electrolytes
  • F2-Isoprostanes
  • Insulin
  • Lipids
  • Phenols
  • Plant Extracts
  • antioxidant biofactor AOB
  • Sodium Chloride
  • Aldosterone
  • Potassium Chloride
  • Renin