Angiotensin I-converting enzyme levels and renin-aldosterone axis recovery after cessation of chronic licorice ingestion

Pseudohyperaldosteronism, liquorice, and hypertension

Consumption of large quantities of liquorice can cause hypokalemia and hypertension. These effects are associated with increased cortisol-mediated activation of renal mineralocorticoid receptors and hypoaldosteronism. The authors describe a patient with long-standing hypokalemia and uncontrolled hypertension related to excessive ingestion of liquorice. The case highlights the importance of obtaining a detailed dietary history, especially considering the increasing use of liquorice-containing foods, teas, and herbal products. The authors also discuss secondary causes of hypertension, focusing on pseudohyperaldosteronism.

The liquorice effect on the RAAS differs between the genders

OBJECTIVE

Liquorice-induced increase in blood pressure (BP) is more profound in subjects with essential hypertension (HT) than in healthy individuals. Liquorice induces pseudohyperaldosteronism by inhibiting the 11beta-hydroxysteroid dehydrogenase type 2 and is also known to inhibit the renin-angiotensin-aldosterone system (RAAS). We explored the difference in response in BP, considering the RAAS and the genders.

DESIGN

Patients with HT (eight men and three women, mean age 40.7 years) and healthy controls (13 men and 12 women, mean age 31.2 years) consumed 100 g of liquorice (150 mg glycyrrhetinic acid) daily for 4 weeks.

METHODS

Blood, urine samples and BP were evaluated before and after 4 weeks of liquorice consumption and 4 weeks after cessation of liquorice consumption.

RESULTS

The relative change in serum aldosterone levels differed between the genders (p < 0.02), men being more responsive than women, but not between patients with HT and healthy subjects.

CONCLUSION

The liquorice-induced inhibition of aldosterone secretion differs between the genders and is not influenced by the BP levels. This difference between the genders has not been exposed before.

Subjects with essential hypertension are more sensitive to the inhibition of 11 beta-HSD by liquorice

In this intervention study, we have investigated if hypertensive patients are more sensitive to liquorice-induced inhibition of 11 beta-hydroxysteroid dehydrogenase (11 beta-HSD) type 2 than normotensive (NT) subjects and if the response depends on gender. Healthy volunteers and patients with essential hypertension (HT), consumed 100 g of liquorice daily, for 4 weeks, corresponding to a daily intake of 150 mg glycyrrhetinic acid. Office, 24-h ambulatory blood pressure (BP) and blood samples were measured before, during and after liquorice consumption. Effect on cortisol metabolism was evaluated by determining the urinary total cortisol metabolites and urinary free cortisol/free cortisone quotient (Q). The mean rise in systolic BP with office measurements after 4 weeks of liquorice consumption was 3.5 mmHg (p<0.06) in NT and 15.3 mmHg (p=0.003) in hypertensive subjects, the response being different (p=0.004). The mean rise in diastolic BP was 3.6 mmHg (p=0.01) in NT and 9.3 mmHg (p<0.001) in hypertensive subjects, the response also being different (p=0.03). Liquorice induced more pronounced clinical symptoms in women than in men (p=0.0008), although the difference in the effect on the BP was not significant. The increase in Q was prominent (p<0.0001) and correlated to the rise in BP (p=0.02). The rise in BP was not dependant on age, the change in plasma renin activity or weight. We conclude that patients with essential HT are more sensitive to the inhibition of 11 beta-HSD by liquorice than NT subjects, and that this inhibition causes more clinical symptoms in women than in men.

Liquorice-induced rise in blood pressure: a linear dose-response relationship

To clarify the dose-response and the time-response relationship between liquorice consumption and rise in blood pressure and explore the inter-individual variance this intervention study was designed and executed in research laboratories at University hospitals in Iceland and Sweden. Healthy, Caucasian volunteers who also served as a control for himself/herself consumed liquorice in various doses, 50-200 g/day, for 2-4 weeks, corresponding to a daily intake of 75-540 mg glycyrrhetinic acid, the active substance in liquorice. Blood pressure was measured before, during and after liquorice consumption. Systolic blood pressure increased by 3.1-14.4 mm Hg (P < 0.05 for all), demonstrating a dose-response but not a time-response relationship. The individual response to liquorice followed the normal distribution. Since liquorice raised the blood pressure with a linear dose-response relationship, even doses as low as 50 g of liquorice (75 mg glycyrrhetinic acid) consumed daily for 2 weeks can cause a significant rise in blood pressure. The finding of a maximal effect of liquorice after only 2 weeks has important implications for all doctors dealing with hypertension. There does not seem to be a special group of responders since the degree of individual response to liquorice consumption followed the normal distribution curve.

Correlation between high intake of glycyrrhizin and myolysis of the papillary muscles: an experimental in vivo study

The ingestion of large quantities of glycyrrhizin, whether as a drug or a sweetener, is known, in susceptible subjects, to induce a syndrome similar to hypermineralcorticoidism, with bouts of hypertension, hypokaliaemia and rabdomyolysis, sometimes associated with severe renal failure and hypokaliaemia-induced arrythmias. Glycyrrhizin is also known to isomerize into the glycyrrhetic (or glycyrrhetinic) acids 18alpha- and 18beta-. In previous works, we reported that these metabolites cause bouts of hypertension and reduction in diuresis at low doses in the rat. In particular, the alpha isomer causes significant elimination of the calcium ion in the urine. The present findings confirm that 18alpha-glycyrrhetic acid is more toxic than either glycyrrhizin or the beta isomer. Histopathological study of tissue samples taken from rats treated with the alpha isomer also reveal selective damage to the myocardium with oedema, myolysis, apoptosis and blistering of the sarcoplasm. These effects begin to appear in the course of subchronic treatment, they manifest themselves in acute treatment and correlate closely with the electrocardiographic changes recorded in rats acutely treated with 18alpha-glycyrrhetic acid.

Hypokaliemic rhabdomyolysis associated with liquorice ingestion: report of an atypical case

We here present an unusual case of hypokaliemic rhabdomyolysis, characterised by a sthenic deficit exclusively involving the distal muscles of the upper limbs and secondary to chronic glycyrrhizic acid intoxication, and by the absence of even ictal arterial hypertension. We discuss the etiopathogenetic bases and the risks related to the development of this secondary hypokaliemic syndrome, also in relation to other concomitant risk factors such as prolonged physical exercise and exposure to low temperatures.