Case of Primary Aldosteronism with Discordant Hormonal and Computed Tomographic Findings

A nonsmoking 46-year-old male was referred to our hypertension excellence center at the Hospital Georges Pompidou in Paris because of hypertension associated with hypokalemia. His past medical history listed asthma treated by inhaled corticosteroid therapy, corneal transplant, and prostatic adenoma. He had neither been diagnosed with diabetes mellitus nor lipid disorder. His body mass index was 24.7 kg/m2. No family history of cardiovascular disease was known. Hypertension was diagnosed incidentally in 2011 at the age of 43 when he consulted his physician for a sport certification. Maximum systolic blood pressure was 190 mm Hg, blood test at that time revealed hypokalemia, with a minimum potassium level of 3 mmol/L. At the time of his first consultation at our department, the patient was already being treated with amlodipine and perindopril once a day. In addition, he received corticoid inhalation for asthma and an α-blocker (tamsulosin) for his prostate adenoma. The patient complained of headaches and dizziness. Diurnal ambulatory blood pressure was very high, 167/112 mm Hg. Blood potassium level was 2.9 mmol/L with inappropriate urinary excretion of potassium (93 mmol/d). Fasting plasma glucose was 5.7 mmol/L, and low-density lipoprotein cholesterol was 3.88 mmol/L. The patient was diagnosed with grade 3 hypertension and hypokalemia. Secondary causes of hypertension were explored, and treatment was modified accordingly. Amlodipine and perindopril administration was terminated, and urapidil was prescribed. Despite oral potassium supplements of 9 g/d, potassium levels remained at 3.0 mmol/L. Estimated glomerular filtration rate was 88 mL min−1 1.73 m−2, and urinary potassium excretion remained elevated (51 mmol/d). Renin and aldosterone levels were assessed in the seated position. Renin was measured at 1.7 mIU/L, and aldosterone at 933 pmol/L (33.7 ng/dL) with an elevated aldosterone:renin ratio. Urinary aldosterone was also elevated (71 mmol/d). And a saline suppression test confirmed the diagnosis of primary aldosteronism with unsuppressed aldosterone secretion at 426 pmol/L (15.7 ng/dL).