Endocrine Abstracts

Apparent mineralocorticoid excess is a rare syndrome with few reported literature entries. Liquorice tea is a common dietary supplement often used as a slimming aid.

We present the case of a 50 year old woman who presented with a two week history of headache, nausea and light sensitivity. Background medical history consisted of irritable bowel syndrome, tubal ligation, thrombosis of a retinal vessel at 17 years of age and a smoker of 10 pack year.

Investigations showed a hypokalaemia of 3.2 mmol/L(normal range 3.5–5.5 mmol/L) in the setting of new hypertension. Mineralocorticoid excess was suspected. Baseline plasma aldosterone <10 pg/mL and plasma renin <2.0 pg/mL.

On further probing she admitted to drinking up to five litres daily of liquorice extract tea.

Repeat testing one month off the tea revealed plasma renin level of 5.5 pg/mL and plasma aldosterone 34 pg/mL, aldosterone renin ratio 6.2. The hypertension and hypokalaemia also resolved.

Liquorice is a known competitive inhibitor of the enzyme 11 beta dehydrogenase 2 which is responsible for conversion of active cortisol to inactive cortisone enabling aldosterone to bind to the mineralocorticoid receptor where normally it would have equal affinity for cortisol and aldosterone.

This case describes liquorice tea- induced apparent mineralocorticoid excess. The case illustrates an unusual cause of new onset hypertension. The importance of careful history taking is also highlighted as essential in correct diagnosis.