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Recommendations Summary

HTN: Potassium 2015

Click here to see the explanation of recommendation ratings (Strong, Fair, Weak, Consensus, Insufficient Evidence) and labels (Imperative or Conditional). To see more detail on the evidence from which the following recommendations were drawn, use the hyperlinks in the Supporting Evidence Section below.


  • Recommendation(s)

    HTN: Dietary Potassium

    The registered dietitian nutritionist (RDN) should encourage adults with hypertension (HTN) to consume adequate amounts of dietary potassium to meet the dietary reference intakes (DRI) to aid in blood pressure (BP) control. Research indicates that potassium excretion as a marker of dietary intake was inversely associated with BP. In a dietary intervention study, increasing potassium intake up to 2, 000mg increased the likelihood of DBP control.

    Rating: Fair
    Imperative

    HTN: Potassium Supplements

    If an adult with HTN is unable to meet the DRI for potassium with diet and food alone, and if not contraindicated by risks and harms, the RDN may consider recommending potassium supplementation of up to 3, 700mg per day to aid in BP control. Research indicates that potassium supplementation up to approximately 3, 700mg reduced SBP and DBP by 3mm Hg to 13mm Hg and 0mm Hg to 8mm Hg, respectively, in adults with HTN. 
     

    Rating: Fair
    Conditional

    • Risks/Harms of Implementing This Recommendation

      Supplementation of potassium or use of potassium-containing salt substitutes may be contraindicated in the following individuals with HTN:

      • Those with certain medical conditions such as renal failure, diabetes mellitus with hyporeninemic hypoaldosteronism and obstructive uropathy, which impair renal excretion of potassium  
      • Those taking medications such as angiotensin-converting enzyme inhibitors, angiotensin II receptor blockers and potassium sparing diuretics, which increase the risk of hyperkalemia (Doorenbos and Vermeij, 2003; Perazella, 2000; Pal et al, 1995; Yap et al, 1976). 

    • Conditions of Application

      • The HTN: Potassium Supplements recommendation applies only to individuals who are unable to meet the DRI for potassium with food intake alone
      • The RDN should consider all sources of dietary potassium, including the use of "lite" salt and potassium-containing salt substitutes.

    • Potential Costs Associated with Application

      If an individual is unable to meet the DRI for dietary potassium, there is an additional cost for potassium supplements.

    • Recommendation Narrative

      A total of 15 studies were included in the evidence analysis supporting these recommendations:

      • Four positive quality randomized crossover trials (Berry et al, 2009; He et al, 2005; He et al, 2009; He et al, 2010) 
      • Two positive quality cross-sectional studies (Kwok et al, 2003; Schroder et al, 2002) 
      • Two positive quality randomized controlled trials (RCTs) (China Salt Substitute Collaborative Group, 2007; Espeland et al, 2002)
      • One positive quality non-randomized controlled trial (Franzoni et al, 2005)
      • One positive quality non-controlled trial (Kelly et al, 2012) 
      • One positive quality meta-analysis (Dickinson et al, 2006) 
      • One positive quality case control study (Cheung et al, 2000)
      • Three neutral quality cross-sectional studies (Hedayati et al, 2012; Hu and Tian, 2001; Lancaster et al, 2004).
      Dietary Potassium  
      • Eight studies were included in the evidence analysis: Berry et al, 2009; Cheung et al, 2000; Espeland et al, 2002; Hedayati et al, 2012; Hu and Tian, 2001; Lancaster et al, 2004; Kwok et al, 2003;  Schroder et al, 2002 
      • Results from six of eight studies, showed a significant inverse relationship between potassium intake from food sources and BP in adults with HTN. Potassium excretion as a marker of dietary intake was inversely associated with BP in four of five studies. In one of two dietary intervention studies, increasing potassium intake of up to 2, 000mg increased the likelihood of DBP control:
        • With dietary intervention,  one of two studies observed beneficial effects of increasing dietary potassium intake on BP (Espeland et al, 2002). Berry et al, 2009 did not observe significant changes in BP with potassium intake.
        • Three studies with dietary intake data showed no significant differences in dietary intake of potassium between normotensive and hypertensive individuals (Hu and Tian 2001; Lancaster et al, 2004; Schroder et al, 2002)
        • Five studies showed showed positive relationships between urinary sodium:potassium ratio and BP (Cheung et al, 2000; Hedayati et al, 2012; Hu and Tian 2001; Kwok et al, 2003; Schroder et al,  2002).
      Potassium Supplementation
      • Eight articles (seven studies) were included in the evidence analysis: Berry et al, 2009; China Salt Substitute Collaborative Group, 2007; Dickinson et al, 2006; Franzoni et al, 2005; He et al, 2005; He et al, 2009; He et al, 2010; Kelly et al, 2012
      • In four of seven studies of adults with HTN potassium supplementation up to approximately 3, 700mg reduced SBP and DBP by 3mm Hg to 13mm Hg and 0mm Hg to 8mm Hg, respectively
        • With potassium supplementation, four of six studies observed decreases in SBP and DBP (China Salt Substitute Collaborative Group, 2007; Fanzoni et al, 2005; He et al, 2005; He et al, 2009; Kelly et al, 2012). He et al, 2009 and Kelly et al, 2012 used same data set.
        • Three studies (including a meta-analysis representing six RCTs) did not observe significant changes in SBP or DBP (Berry et al, 2010; Dickinson et al, 2006; He, Marciniak et al, 2010)
        • One study found a positive relationship between urinary sodium and potassium excretion and BP (Franzoni et al, 2005)

    • Recommendation Strength Rationale

      Conclusion statements for HTN: Dietary Potassium and HTN: Potassium Supplements are Grade II.

    • Minority Opinions

      None.