• 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.
    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.
    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.