Sodium

NA: Sodium or Sodium Chloride (2010)

• Assessment
  Is there a relationship between sodium or sodium chloride intake and blood pressure in hypertensive adults?

  • Conclusion

    In 15 studies of hypertensive adults,* a lower sodium or sodium chloride intake was associated with significantly lower blood pressure (BP) (-1.3mmHg to -16.8mmHg SBP; -1.9mmHg to -10.7mmHg DBP). Factors that affect this relationship included dietary pattern, race, ethnicity and age of subjects. In studies comparing blood pressure response to varying levels of sodium or sodium chloride intake, lowered blood pressures were noted with reduction in sodium intakes from (120mmol to 350mmol to 30mmol to 330mmol). A greater BP-lowering response was observed in the following groups: Those consuming a low-sodium diet with their usual dietary pattern vs. a DASH dietary pattern in black subjects and in older subjects.

    * Definition of hypertension varied by study, country or version of JNC report.

    See Table: Sodium and Blood Pressure Response

  • Grade: I
    • Grade I means there is Good/Strong evidence supporting the statement;
    • Grade II is Fair;
    • Grade III is Limited/Weak;
    • Grade IV is Expert Opinion Only;
    • Grade V is Not Assignable.
    • High (A) means we are very confident that the true effect lies close to that of the estimate of the effect;
    • Moderate (B) means we are moderately confident in the effect estimate;
    • Low (C) means our confidence in the effect estimate is limited;
    • Very Low (D) means we have very little confidence in the effect estimate.
    • Ungraded means a grade is not assignable.
  • Evidence Summary: Sodium Intake and Blood Pressure in Hypertensive Adults
    • Detail
    • Quality Rating Summary
      For a summary of the Quality Rating results, click here.
    • Worksheets
      • Appel LJ, Espeland MA, Easter L, Wilson AC, Folmar S, Lacy CR. Effects of reduced sodium intake on hypertension control in older individuals:  results from the Trial of Nonpharmacologic Interventions in the Elderly (TONE). Arch Intern Med. 2001 Mar 12; 161 (5): 685-693.
      • Bray GA, Vollmer WM, Sacks FM, Obarzanek E, Svetkey LP, Appel LJ. A further subgroup analysis of the effects of the DASH diet and three dietary sodium levels on blood pressure: Results of the DASH-sodium trial. AM J Cardiol. 204 Jul 15; 94(2): 222-227.
      • Cheung BMY, Ho SPC, Cheung AHK, Lau CP. Diastolic blood pressure is related to urinary sodium excretion in hypertensive Chinese patients.  Q J Med. 2000; 93: 163-168.
      • Coruzzi P, Brambilla L, Brambilla V, Gualerzi M, Rossi M, Parati G, Di Rienzo M, Tadonio J, Novarini A. Potassium depletion and salt sensitivity in essential hypertension. J Clin Endocrinol Metab. 2001 Jun; 86(6): 2,857-2,862.
      • Espeland MA, Kumanyika S, Yunis C, Zheng B, Brown WM, Jackson S, Wilson AC, Bahnson J, Electrolyte intake and nonpharmacologic blood pressure control. Ann Epidemiol. 2002; 12: 587-595. 
      • Geleijnse JM, Kok FJ, Grobbee DE. Blood pressure response to changes in sodium and potassium intake: a metaregression analysis of randomised trials. Journal of Human Hypertension, 2003; 17: 471-480.
      • Geleijnse JM, Kok FJ, Grobbee DE. Impact of dietary and lifestyle factors on the prevalence of hypertension in Western populations. Eur J Public Health. 2004; 14 (3): 235-239. 
      • He FJ, MacGregor GA. Effect of longer-term modest salt reduction on blood pressure. Cochrane Database Syst Rev. 2004; (1): CD004937. PMID: 15266549 
      • He FJ, MacGregor GA. How far should salt intake be reduced? Hypertension, 2003; 42: 1,093-1,099.
      • He FJ, Markandu ND, MacGregor GA. Importance of the renin system for determining blood pressure fall with acute salt restriction in hypertensive and normotensive whites. Hypertension. 2001 Sep; 38 (3): 321-325.
      • Hu G, Tian H. A comparison of dietary and non-dietary factors of hypertension and normal blood pressure in a Chinese population. Journal of Human Hypertension, 2001; 15: 487-493.
      • Jürgens G, Graudal NA. Effects of low sodium diet versus high sodium diet on blood pressure, renin, aldosterone, catecholamines, cholesterols, and triglyceride. Cochrane Database Syst Rev. 2003; (1): CD004022. Review. Update in: Cochrane Database Syst Rev. 2004; (1): CD004022
      • Liu L, Liu L, Ding Y, Huang Z, He B, Sun S, Zhao G, Zhang H, Miki T, Mizushima S, Ikeda K, Nara Y, Yamori Y. Ethnic and environmental differences in various markers of dietary intake and blood pressure among Chinese Han and three other minority peoples of China: results from the WHO Cardiovascular Diseases and Alimentary Comparison (CARDIAC) Study. Hypertens Res. 2001; 24 (3): 315-322.
      • Radhika G, Sathya RM, Sudha V, et al. Dietary salt intake and hypertension in an urban south Indian population. J Assoc Physicians India. 2007; 55: 405-411.
      • Sacks FM, Svetkey LP, Vollmer WM, Appel LJ, Bray GA, Harsha D, Obarzanek E, Conlin PR, Miller III ER, Simons-Morton DG, Karanja N, Lin PH. Effects on blood pressure of reduced dietary sodium and the Dietary Approaches to Stop Hypertension (DASH) Diet. N Engl J Med. 2001; 344:3-10.
  • Search Plan and Results: NA: Sodium and Blood Pressure Update 2009
     
  Is there a relationship between sodium or sodium chloride intake and blood pressure in normotensive adults?

  • Conclusion

    In four out of five studies of normotensive* adults, a lower sodium or sodium chloride intake resulted in significantly lower blood pressure (BP) (-1.0 to -10.5mm Hg SBP; -0.8 to -5.3mm Hg DBP). Lowered blood pressures were noted with reductions in sodium or sodium chloride intake from 150 to 220mmol to 20 to 120mmol. Factors that affect this relationship included dietary pattern, race, ethnicity and age of subjects. A greater BP-lowering response was observed in the following groups:

    • Those with a higher initial level of sodium intake
    • Those consuming a low sodium diet with their usual dietary pattern vs. a DASH dietary pattern
    • In black subjects
    • In older subjects.

    * In some studies, NTN may also include PHTN due to changes in the definition of each.  

    See Table: Sodium and Blood Pressure Response

  • Grade: I
    • Grade I means there is Good/Strong evidence supporting the statement;
    • Grade II is Fair;
    • Grade III is Limited/Weak;
    • Grade IV is Expert Opinion Only;
    • Grade V is Not Assignable.
    • High (A) means we are very confident that the true effect lies close to that of the estimate of the effect;
    • Moderate (B) means we are moderately confident in the effect estimate;
    • Low (C) means our confidence in the effect estimate is limited;
    • Very Low (D) means we have very little confidence in the effect estimate.
    • Ungraded means a grade is not assignable.
  • Evidence Summary: What evidence suggests a relationship between sodium or sodium chloride intake and blood pressure in normotensive adults?
    • Detail
    • Quality Rating Summary
      For a summary of the Quality Rating results, click here.
    • Worksheets
      • Bray GA, Vollmer WM, Sacks FM, Obarzanek E, Svetkey LP, Appel LJ. A further subgroup analysis of the effects of the DASH diet and three dietary sodium levels on blood pressure: Results of the DASH-sodium trial. AM J Cardiol. 204 Jul 15; 94(2): 222-227.
      • He FJ, MacGregor GA. Effect of longer-term modest salt reduction on blood pressure. Cochrane Database Syst Rev. 2004; (1): CD004937. PMID: 15266549 
      • He FJ, MacGregor GA. How far should salt intake be reduced? Hypertension, 2003; 42: 1,093-1,099.
      • Jessani S, Hatcher J, Chaturvedi N, Jafar TH. Effect of low vs. high dietary sodium on blood pressure levels in a normotensive Indo-Asian population. Am J Hypertens. 2008;21(11):1238-1244. Epub 2008 Sep 4.
      • Jürgens G, Graudal NA. Effects of low sodium diet versus high sodium diet on blood pressure, renin, aldosterone, catecholamines, cholesterols, and triglyceride. Cochrane Database Syst Rev. 2003; (1): CD004022. Review. Update in: Cochrane Database Syst Rev. 2004; (1): CD004022
  • Search Plan and Results: NA: Sodium and Blood Pressure Update 2009
     
  Is there a relationship between sodium or sodium chloride intake and blood pressure in pre-hypertensive adults?

  • Conclusion

    In 10 out of 11 studies of pre-hypertensive* adults, a lower sodium or sodium chloride intake was associated with significantly lower blood pressure (BP) (-1.0mmHg to -10mmHg SBP; -1.0 mmHg to -5.0mmHg DBP). In studies comparing blood pressure response to varying levels of sodium or sodium chloride intake, lowered blood pressures were noted with reduction in sodium intakes from 154mmol to 300mmol to 20mmol to 82mmol. Factors that affect this relationship included dietary pattern, race, ethnicity and age of subjects. A greater BP-lowering response was observed in the following groups: Those consuming a low-sodium diet with their usual dietary pattern vs. a DASH dietary pattern in black subjects and in older subjects.

    * In some studies, PHTN may also include NTN, due to changes in the definition of each.

    See Table: Sodium and Blood Pressure Response

  • Grade: I
    • Grade I means there is Good/Strong evidence supporting the statement;
    • Grade II is Fair;
    • Grade III is Limited/Weak;
    • Grade IV is Expert Opinion Only;
    • Grade V is Not Assignable.
    • High (A) means we are very confident that the true effect lies close to that of the estimate of the effect;
    • Moderate (B) means we are moderately confident in the effect estimate;
    • Low (C) means our confidence in the effect estimate is limited;
    • Very Low (D) means we have very little confidence in the effect estimate.
    • Ungraded means a grade is not assignable.
  • Evidence Summary: Sodium Intake and Blood Pressure in Pre-hypertensive Adults
    • Detail
    • Quality Rating Summary
      For a summary of the Quality Rating results, click here.
    • Worksheets
      • Bray GA, Vollmer WM, Sacks FM, Obarzanek E, Svetkey LP, Appel LJ. A further subgroup analysis of the effects of the DASH diet and three dietary sodium levels on blood pressure: Results of the DASH-sodium trial. AM J Cardiol. 204 Jul 15; 94(2): 222-227.
      • Cook NR, Obarzanek E, Cutler JA, Buring JE, Rexrode KM, Kumanyika SK, Appel LJ, Whelton PK. Joint effects of sodium and potasium intake on subsequent cardiovascular disease: The Trials of Hypertension Prevention Follow-up Study. Archives of Internal Medicine. 2009 Jan 12; 169(1): 32-40.
      • Geleijnse JM, Kok FJ, Grobbee DE. Blood pressure response to changes in sodium and potassium intake: a metaregression analysis of randomised trials. Journal of Human Hypertension, 2003; 17: 471-480.
      • He FJ, MacGregor GA. Effect of longer-term modest salt reduction on blood pressure. Cochrane Database Syst Rev. 2004; (1): CD004937. PMID: 15266549 
      • He J, Whelton PK, Appel LJ, Charleston J, Klag MJ. Long-term effects of weight loss and dietary sodium reduction on incidence of hypertension. Hypertension, 2000; 35: 544-549.  
      • Jessani S, Hatcher J, Chaturvedi N, Jafar TH. Effect of low vs. high dietary sodium on blood pressure levels in a normotensive Indo-Asian population. Am J Hypertens. 2008;21(11):1238-1244. Epub 2008 Sep 4.
      • Johnson AG, Nguyen TV, Davis D. Blood pressure is linked to salt intake and modulated by the angiotensinogen gene in normotensive and hypertensive elderly subjects. J Hypertens. 2001 Jun; 19 (6): 1,053-1,060.
      • Khaw KT, Bingham S, Welch A, Luben R, O'Brien E, Wareham N, Day N. Blood pressure and urinary sodium in men and women: the Norfolk Cohort of the European Prospective Investigation into Cancer (EPIC-Norfolk). Am J Clin Nutr. 2004; 80: 1,397-1,403. 
      • Liu L, Liu L, Ding Y, Huang Z, He B, Sun S, Zhao G, Zhang H, Miki T, Mizushima S, Ikeda K, Nara Y, Yamori Y. Ethnic and environmental differences in various markers of dietary intake and blood pressure among Chinese Han and three other minority peoples of China: results from the WHO Cardiovascular Diseases and Alimentary Comparison (CARDIAC) Study. Hypertens Res. 2001; 24 (3): 315-322.
      • Radhika G, Sathya RM, Sudha V, et al. Dietary salt intake and hypertension in an urban south Indian population. J Assoc Physicians India. 2007; 55: 405-411.
      • Sacks FM, Svetkey LP, Vollmer WM, Appel LJ, Bray GA, Harsha D, Obarzanek E, Conlin PR, Miller III ER, Simons-Morton DG, Karanja N, Lin PH. Effects on blood pressure of reduced dietary sodium and the Dietary Approaches to Stop Hypertension (DASH) Diet. N Engl J Med. 2001; 344:3-10.
  • Search Plan and Results: NA: Sodium and Blood Pressure Update 2009