Primary hyperaldosteronism as a rare cause of hypokalemia

Primary hyperaldosteronism (PHA) is a syndrome characterized by increased aldosterone release andsuppressed renin-angiotensin cascade. Hypertension, alteration in potassium homeostasis, and target tissuedamage are characteristic features of the disease. The importance of recognizing PHA is due to the fact that ithas a very negative cardiovascular and renal effect which can result in death. In this case report, we presenta patient with resistant hypokalemia whom consequently diagnosed with PHA. A 54-year-old female patientwho was scheduled for operation due to congenital hip dislocation was found to have decreased serum potassiumin her preoperative laboratory tests. Therefore, the patient was referred to the internal medicine outpatientclinic with a serum potassium value of 2.1 mmol/L. Her systolic and diastolic blood pressures were 150 and90 mmHg, respectively. On electrocardiogram, prominent U waves were noted. Therefore, potassium replacementwas initiated at once by intravenous route. The potassium value in spot urine was 12.4 mmol/L. A 24 hoururine collected and urinary potassium excretion in 24 hours of urine was detected as 15 mmol/L, which meanstranstubular potassium gradient was greater than 4 mmol/L. Since she was hypertensive during clinical followup in the ward, hypertension along with hypokalemia raised the clinical suspicion of hyperaldosteronism.Serum aldosterone renin ratio was measured as 155 %. A computerized tomography scan revealed (22 × 16 mm)neoplasm which was suggestive of adrenal adenoma in the right adrenal gland. Cushing Syndrome was ruledout with a normal cortisol level and pheochromocytoma was ruled out by normal levels of metanephrine in the24 hours of urine. Spironolactone 50 mg was initiated and serum potassium was raised to normal range. Shescheduled for unilateral adrenalectomy and discharged with full recovery of hypokalemia. Since PHA has undesiredcardiovascular and renal effects which may increase mortality and morbidity, establishing the diagnosisas soon as possible is crucial. Hypertensive patients with hypokalemia or adrenal incidentaloma or obstructivesleep apnea syndrome, resistant hypertensive subjects, patients with moderate or severe hypertension, and hypertensive patients with a family history of PHA should undergo screening for PHA. In conclusion, we suggestthat PHA should be kept in mind in differential diagnosis of the patients with hypertension and hypokalemia.