Licorice - or more?

Abstract

A 57 yr old man presented to endocrinology clinic with a six year history of poorly controlled hypertension which was treated with Metoprolol 200 mg/day and Enalapril 20 mg/day. He was asymptomatic but incidentally hypokalaemia was detected while having cholecystectomy, two years prior to his clinic appointment. He had never been on diuretics or laxatives. He was started on potassium supplements (120 mmol/d) and advised to increase dietary potassium by the surgical team. A detailed personal history revealed ingestion of 300-500 g licorice per day. Physical examination was unremarkable apart from increased blood pressure of 180/105 mmHg. Following the initial visit, his serum electrolyes (K+3.7 mmol/l) were normal with potassium supplementation and as were morning cortisol, ACTH, 11-deoxycortisol and plasma metanephrines. 17 OH-P, DHEAS and androstenedione were normal but testosterone was low. Morning ambulant aldosterone was slightly increased at 801 pmol/L and renin activity was undetectable. Urinary 24 h aldosterone excretion was significantly increased at 162 ng/24 h with normal cortisol and catecholamine excretion. Four weeks following advice to stop licorice, serum potassium decreased to 3.4 mmol/L despite continuous supplementation. Morning plasma aldosterone increased to 1 449 pmol/ml, renin activity remained undetectable but 24 h urine aldosterone excretion increased to 434 ng/24 h with a reduction in urinary cortisol excretion. Interestingly 17 OH-P and androstenedione levels, although within the reference range, were slightly higher compared to the levels whilst on licorice. Testosterone level had significantly increased to be within normal range. Abdominal imaging with US and MRI showed a 2.7 cmx2.2 cmx1.7 cm left adrenal mass. He underwent laparoscopic left adrenalectomy and histology confirmed aldosterone producing adrenal adenoma. Post-operatively his aldosterone and serum potassium levels normalized and he became normotensive without any antihypertensive medication.