Endocrine Abstracts

Primary aldosteronism (PA) is a highly prevalent syndrome which is often missed even in those that present classically due to poor awareness. The commonest initial presentation is varied degree of hypertension with hypokalaemia in only 37%. The presence of hypokalaemia could be a good pointer to the diagnosis of PA but it is not a common initial presentation in normotensive patients. We present a 22-year-old man who presented initially with refractory normotensive hypokalaemic metabolic alkalosis after recurrent episodes of vomiting. It was initially felt that hypokalaemia was likely due to vomiting, however, the vomiting settled relatively quickly, but there was persistent refractory hypokalaemia despite large amounts of potassium supplementations on admission. Oesophago-gastroduodenoscopy showed oesophageal reflux. There is no any medical history, no regular medication, no abuse of diuretic or laxatives, or liquorice but significant history of hypertension and stroke in father with mortality at age 45. The initial investigations include nadir potassium of 2.6, pH of 7.44, bicarbonate 30.3 and base excess of +9.1, high renal potassium level of 92.2 mmol/l, normal plasma and urinary Magnesium and calcium, negative porphyria screen. He was referred to Endocrine clinic due to high ARR of 413.9 (<91) with normal Blood Pressure (BP). Consequently, he had saline suppression test which showed basal suppressed renin (2.0 mU/l), raised aldosterone (1320 pmol/l with failure of complete suppression of aldosterone after saline infusion (819 pmol/l) and overnight Dexamethasone suppression test (Cortisol 33). The initial adrenal CT was inconclusive and thus had an adrenal MRI which showed 15 mm adenoma. 24hr BP was normal with overall mean of 132/81 and the case was discussed at the regional Neuroendocrine MDT. The diagnosis of Conn’s disease could not be made due to normal BP and possibility of renal tubulopathy (Gitelman’s) was suggested. Eplerenone was started which maintained the potassium in the relatively normal range. This was continued for 2 years until high Blood pressure was picked up on home BP machine despite being on 150 mg of Eplerenone daily. This was optimised with further titration of Eplerenone and amlodipine. He was thereafter referred to a national expert who agreed with the diagnosis of PA and recommended genetic testing for a familial aldosteronism (type 1) before proceeding to surgery which eventually came back negative. This case illustrates the potential dilemma and delays that could further be encountered in diagnosis and management of PA with non-classical presentation.