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Recommendations Summary

HTN: Caffeine 2008

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: Caffeine Intake

  For those who consume caffeine, advise blood pressure monitoring; while acute intake of caffeine increases blood pressure, the effect of chronic caffeine intake is unclear.

  Rating: Weak
  Conditional

  • Risks/Harms of Implementing This Recommendation

    None.

  • Conditions of Application

    Recommendation applies to those who consume caffeine.

  • Potential Costs Associated with Application

    None.

  • Recommendation Narrative

    • Five studies investigating acute effects of caffeine reported an increase in systolic or diastolic blood pressure at doses varying from 3.3mg per kg to fixed doses of 250-300 mg (Shepard et al, 2000; Watson et al, 2002; Vlachopoulos et al, 2003; Waring et al, 2003; Hartley et al, 2004), with one meta-analysis reporting a more pronounced blood pressure increase in hypertensive subjects as compared to healthy subjects (Hartley et al, 2000).  
    • Two studies investigated the effect of 1 week of caffeine consumption on blood pressure.  One randomized controlled trial reported that daily caffeine exposure did not mitigate the acute rise in systolic or diastolic blood pressure after single caffeine challenge (Watson et al, 2002), while a nonrandomized clinical trial reported only an increase in diastolic blood pressure which dissipated over seven days of continued caffeine consumption (Cavalcante et al, 2000).  
    • One meta-analysis of caffeine and coffee consumption for at least seven days reported a significant rise of ~2mm Hg in systolic blood pressure and ~1mm Hg in diastolic blood pressure. A greater effect was noted for caffeine supplement consumption than for coffee consumption (Noordzij et al, 2005).  

  • Recommendation Strength Rationale

    • Conclusion Statement is Grade III

  • Minority Opinions

    Consensus reached.

• Supporting Evidence

  The recommendations were created from the evidence analysis on the following questions. To see detail of the evidence analysis, click the blue hyperlinks below (recommendations rated consensus will not have supporting evidence linked).

  What is the relationship between caffeine intake and blood pressure in healthy and hypertensive adults?

  • References

    Cavalcante JWS, Santos PRM, de Menezes MGF, Marques HO, Cavalcante LP, Pacheco WS. Influence of caffeine on blood pressure and platelet aggregation. Arq Bras Cardiol. 2000; 75: 102-105.
    
    Hartley TR, Lovallo WR, Whitsett TL. Cardiovascular effects of caffeine in men and women. Am J Cardiol. 2004; 93: 1,022-1,026.
    
    Hartley TR, Sung BH, Pincomb GA, Whitsett TL, Wilson MF, Lovallo WR. Hypertension risk status and effect of caffeine on blood pressure. Hypertension, 2000; 36: 137-141.
    
    Noordzij M, Uiterwaal CSPM, Arends LR, Kok FJ, Grobbee DE, Geleijnse JM. Blood pressure response to chronic intake of coffee and caffeine: a meta-analysis of randomized controlled trials. J Hypertension. 2005; 23: 921-928.
    
    Shepard JD, al'Absi M, Whitsett TL, Passey RB, Lovallo WR. Additive pressor effects of caffeine and stress in male medical students at risk for hypertension. Am J Hypertens. 2000; 13: 475-481.
    
    Vlachopoulos C, Hirata K, Stefanadis C, Toutouzas P, O'Rourke MF. Caffeine increases aortic stiffness in hypertensive patients. Am J Hpertens. 2003; 16: 63-66.
    
    Waring WS, Goudsmit J, Marwick J, Webb DJ, Maxwell SRJ. Acute caffeine intake influences central more than peripheral blood pressure in young adults. Am J Hypertens. 2003; 16: 919-924.
    
    Watson J, Deary I, Kerr D. Central and peripheral effects of sustained caffeine use: tolerance is incomplete. Br J Clin Pharmacol. 2002; 54: 400-406.

  • References not graded in Academy of Nutrition and Dietetics Evidence Analysis Process

    None.