PRIMARY HYPERALDOSTERONISM AS A RARE CAUSE OF HYPOKALEMIA
Keywords:hypokalemia, primary hyperaldosteronism, secondary hypertension
Primary hyperaldosteronism (PHA) is a syndrome characterized by increased aldosterone release and
suppressed renin-angiotensin cascade. Hypertension, alteration in potassium homeostasis, and target tissue
damage are characteristic features of the disease. The importance of recognizing PHA is due to the fact that it
has a very negative cardiovascular and renal effect which can result in death. In this case report, we present
a patient with resistant hypokalemia whom consequently diagnosed with PHA. A 54-year-old female patient
who was scheduled for operation due to congenital hip dislocation was found to have decreased serum potassium
in her preoperative laboratory tests. Therefore, the patient was referred to the internal medicine outpatient
clinic with a serum potassium value of 2.1 mmol/L. Her systolic and diastolic blood pressures were 150 and
90 mmHg, respectively. On electrocardiogram, prominent U waves were noted. Therefore, potassium replacement
was initiated at once by intravenous route. The potassium value in spot urine was 12.4 mmol/L. A 24 hour
urine collected and urinary potassium excretion in 24 hours of urine was detected as 15 mmol/L, which means
transtubular potassium gradient was greater than 4 mmol/L. Since she was hypertensive during clinical follow
up 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 ruled
out with a normal cortisol level and pheochromocytoma was ruled out by normal levels of metanephrine in the
24 hours of urine. Spironolactone 50 mg was initiated and serum potassium was raised to normal range. She
scheduled for unilateral adrenalectomy and discharged with full recovery of hypokalemia. Since PHA has undesired
cardiovascular and renal effects which may increase mortality and morbidity, establishing the diagnosis
as soon as possible is crucial. Hypertensive patients with hypokalemia or adrenal incidentaloma or obstructive
sleep 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 suggest
that PHA should be kept in mind in differential diagnosis of the patients with hypertension and hypokalemia.
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