How does excess licorice consumption cause hypertension and hypokalemia?

The active ingredient of licorice, glycyrrhizic acid or glycyrrhizin, is first converted to glycyrrhetinic acid (GRA) in the bowel which is then absorbed. Once in the circulation, GRA inhibits activation of 11 β-hydroxysteroid dehydrogenase 2 (11 β-HSD2), an enzyme in renal tissue that converts active cortisol to inactive cortisone. Without the full action of this enzyme, proper sodium and potassium homeostasis would be difficult because cortisol is just as effective in stimulating mineralocorticoid receptors as aldosterone but with 100-1000 times higher concentration than that of aldosterone! 1-3

Other ways that GRA may cause hypertension and hypokalemia include inhibition of 5 β-reductase in the liver, an enzyme that metabolizes aldosterone and direct stimulation of mineralocorticoid receptors, though overall these mechanisms may not be as important as the effect of GRA on cortisol metabolism in renal tissue.1,2

Besides causing fluid retention, licorice ingestion has also been found to increase systemic vascular resistance possibly by increasing vascular tone and remodeling of the vascular wall, potentiating the vasoconstrictor actions of angiotensin II and catecholamines in smooth muscle, and suppressing vasodilatory systems, including endothelial nitric oxide synthase and prostacyclin synthesis.

It’s no wonder that the FDA issued a statement in 2017: “If you’re 40 or older, eating 2 ounces of black licorice a day for a day for at least two weeks could land you in the hospital with an irregular heart rhythm or arrhythmia.” 5

Bonus Pearl: Did you know that as early as 1951, extract of licorice was reported for treatment of Addison’s disease, a combination of licorice and soy sauce has been reported to be “life-saving” in a patient with Addison’s disease (2007), and GRA food supplementation may lower serum potassium in chronic hemodialysis patients (2009)? 6,7

 

References

  1. Sontia B, Mooney J, Gaudet L, et al. Pseudohyperaldosteronism, liquorice and hypertension. J Clin Hypertens (Greenwich) 2008; 10:153-57. https://www.ncbi.nlm.nih.gov/pubmed/18256580
  2. Omar HR, Komarova I, El-Ghonemi M, et al. Licorice abuse: time to send a warning message. The Adv Endocrinol Metab 2012;3:125-138. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3498851/
  3. Penninkilampi R, Eslick EM, Eslick GD. The association between consistent licorice ingestion, hypertension and hypokalaemia: as systematic review and meta-analysis. Journal of Human Hypertension 2017;31:699-707. https://www.ncbi.nlm.nih.gov/pubmed/28660884
  4. Black licorice: trik or treat? https://www.fda.gov/ForConsumers/ConsumerUpdates/ucm 277152.htm
  5. Hautaniemi EJ, Tahvanainen AM, Koskela JK, et al. Voluntary liquorice ingestion increases blood pressure via increased volume load, elevated peripheral arterial resistance, and decreased aortic compliance. Sci Rep 2017;7:10947. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5591274/
  6. Groen J, Pelser H, Willebrands AF, et al. Extract of licorice for the treatment of Addison’s disease. N Engl J Med 1951;244:471-75. https://www.ncbi.nlm.nih.gov/pubmed/14806786
  7. Cooper H, Bhattacharya B, Verma V, et al. Liquorice and soy sauce, a life-saving concoction in a patient with Addison’s disease. Ann Clin Biochem 2007;44:397-99. https://www.ncbi.nlm.nih.gov/pubmed/17594790
  8. Farese S, Kruse Anja, Pasch A, et al. Glycyrrhetinic acid food supplementation lowers serum potassium concentration in chronic hemodialysis patients. Kidney International 2009;76:877-84. https://www.ncbi.nlm.nih.gov/pubmed/19641483
How does excess licorice consumption cause hypertension and hypokalemia?

Should my patient with compensated heart failure be placed on a sodium-restricted diet?

Although sodium restriction is routinely recommended for patients with heart failure (HF), the data is often conflicting with a number of studies even suggesting that it may be harmful in some patients.

Two randomized trials (by the same group) involving patients with compensated HF recently discharged from the hospital reported that “less restricted” sodium diet (2.8 gm/d) along with fluid restriction (1 L/day) and high dose furosemide (at least 125-250 mg furosemide twice daily) was associated with less rates of readmissions and improved levels of brain natriuretic peptide, aldosterone and plasma renin activity compared to patients on more restricted sodium diet (1.8 gm/d). 1,2

Analysis of data from the multihospital HF Adherence and Retention Trial enrolling New York Heart Association functional class II/III HF patients found that sodium restriction (<2.5 gm/d) was associated with significantly higher risk of death or HF hospitalization but only in patients not on an angiotensin converting enzyme inhibitor (ACEI) or angiotensin receptor blocker (ARB). 3

In normal subjects who are not sodium deprived, excess sodium intake has been shown to cause expansion of intravascular volume without increasing total body water. 4 Thus, sodium restriction combined with diuretics may reduce intravascular volume and renal perfusion, further stimulating the renin-angiotensin-aldosterone system and fluid retention. 5

Bonus Pearl: Did you know that the 2013 American College of Cardiology Foundation/American Heart Association guidelines downgraded the recommendation for sodium restriction to Class IIa (reasonable) with Level of Evidence:C? 6

References

  1. Paterna S, Gaspare P, Fasullo S, et al. Normal-sodium diet compared with low-sodium diet in compensated congestive heart failure: is sodium an old enemy or a new friend? Clin Sci 2008;114:221-230. https://www.ncbi.nlm.nih.gov/pubmed/17688420
  2. Paterna S, Parrinello G, Cannizzaro S, et al. Medium term effects of different dosage of diuretic, sodium, and fluid administration on neurohormonal and clinical outcome in patients with recently compensated heart failure. Am J Cardiol 2009;103:93-102. https://www.ncbi.nlm.nih.gov/pubmed/19101237
  3. Doukky R, Avery E, Mangla A, et al.Impact of dietary sodium restriction on heart failure outcomes. J Am Coll Cariol HF 2016;4:24-35. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4705447/
  4. Heer M, Baisch F, Kropp J et al. High dietary sodium chloride consumption may not induce body fluid retention in humans. Am J Physiol Renal Physiol 2000;278:F585-F595. https://www.ncbi.nlm.nih.gov/pubmed/10751219
  5. Rothberg MB, Sivalingam SK. The new heart failure diet: less salt restriction, more micronutrients. J Gen Intern Med 25;1136-7. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2955483/
  6. Yancy CW, Jessup M, Bozkurt B, et al. 2013 CCF/AHA guideline for the management of heart failure: a report of the American College of Cardiology Foundation/American Heart Association Task Force on Practice Guidelines. J Am Coll Cardiol 2013;62:e147-239. https://www.ncbi.nlm.nih.gov/pubmed/23741058

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Should my patient with compensated heart failure be placed on a sodium-restricted diet?

Why isn’t my patient with congestive heart failure or end-stage liver disease losing weight despite being on diuretic therapy? Is the diuretic dose too low, or is the salt intake too high?

When a patient with congestive heart failure (CHF) or end-stage liver disease (ESLD) doesn’t respond as expected to diuretic therapy, measurement of urinary sodium (Na) can be helpful.

In low effective arterial blood volume states (eg, CHF and ESLD) aldosterone secretion is high, resulting in high urine potassium (K) and low urine Na concentrations. However, in the presence of diuretics, urinary Na excretion should rise.

Patients undergoing active diuresis are often restricted to a 2 g (88 mEq) Na intake/day, with ~10 mEq excreted via non-urinary sources (primarily stool), and ~ 78 mEq excreted in the urine to “break even” — that is, to maintain the same weight.

Although historically measured 1, a 24-hour urine Na and K collection is tedious, making spot urine Na/K ratio more attractive as a potential proxy.  Approximately 90% of patients who achieve a urinary Na/K ratio ≥1 will have a urinary Na excretion ≥78 mEq/day — that is to say, they are sensitive to the diuretic and will have a stable or decreasing weight at the current dose. 2,3

Urine Na/K may be interpreted as follows:

  • ≥1 and losing weight suggests effective diuretic dose, adherent to low Na diet
  • ≥1 and rising weight suggests effective diuretic dose, non-adherent to low Na diet
  • <1 and rising weight suggests ineffective diuretic dose

The “ideal” Na/K ratio as relates to responsiveness to diuretics has ranged from 1.0 to 2.5.4 In acutely decompensated heart failure patients on spironolactone, a K-sparing diuretic, Na/K ratio >2 at day 3 of hospitalization may be associated with improved outcome at 180 days. 5

Remember also that if the patient’s clinical syndrome is not correlating well with the ratio, it’s always a good idea to proceed to a 24-hour urine collection.

 

References

  1. Runyon B. Refractory Ascites. Semin Liver Dis. Semin Liver Dis. 1993 Nov;13(4):343-51. https://www.ncbi.nlm.nih.gov/pubmed/8303315
  2. Stiehm AJ, Mendler MH, Runyon BA. Detection of diuretic-resistance or diuretic-sensitivity by spot urine Na/K ratios in 729 specimens from cirrhotics with ascites: approximately 90 percent accuracy as compared to 24-hr urine Na excretion (abstract). Hepatology 2002; 36: 222A.
  3. da Silva OM, Thiele GB, Fayad L. et al. Comparative study of spot urine Na/K ratio and 24-hour urine sodium in natriuresis evaluation of cirrhotic patients with ascites. GE J Port Gastroenterol 2014;21:15-20 https://pdfs.semanticscholar.org/4dc3/4d18d202c6fa2b30a1f6563baab80d877921.pdf
  4. El-Bokl M, Senousy, B, El-Karmouty K, Mohammed I, Mohammed S, Shabana S, Shelby H. Spot urinary sodium for assessing dietary sodium restriction in cirrhotic ascites. World J Gastroenterol 2009; 15:3631. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2721236/
  5. Ferreira JP, Girerd N, Medeiros PB, et al. Spot urine sodium excretion as prognostic marker in acutely decompensated heart failure: the spironolactone effect. Clin Res Cardiol 2016;105:489-507. https://www.ncbi.nlm.nih.gov/pubmed/26615605

 

Contributed by Alyssa Castillo, MD, with valuable input from Sawalla Guseh, MD, both from Mass General Hospital, Boston, MA.

Why isn’t my patient with congestive heart failure or end-stage liver disease losing weight despite being on diuretic therapy? Is the diuretic dose too low, or is the salt intake too high?