Endocrine Abstracts

Background: Hypokalemia is a chronic condition in primary aldosteronism (PA) and hypokalemia symptoms usually can be tolerated by the patients. Hypokalemic periodic paralysis due to primary aldosteronism is rarely reported. We reported two cases of hypokalemic paralysis due to primary aldosteronism.

Case 1: A 33-year-old male admitted to the emergency service with fatigue, numbness, progressive weakness in his legs and arms for 2 months. He had a hypertension for 8 years and his medications were triple antihypertensive. On physical examination his blood pressure was140/90 mm Hg, upper and lower extremity muscle strength loss. Laboratory results were revealed low potassium levels (1.4 mEq/l) and high creatine phosphokinase (CPK) levels (1465 IU/l). The patient was hospitalized with a prediagnosis of hypokalemic periodic paralysis. After normalizing potassium level plasma aldosterone concentration (PAC) and plasma renin activity (PRA) were 60 ng/dl (7–30 ng/dl) and 0.6 ng/ml per h (0.7–3.3 ng/ml per h), respectively and PAC:PRA ratio was 100 and saline infusion test was confirmed primary aldosteronism. MRI revealed a 12 mm adenoma in left surrenal. Left surrenalectomy was performed after 200 mg/day spironolactone treatment. Post-operative pathology result was adrenal cortical adenoma.

Case 2: A 39-year-old woman applied to hospital with recurrent muscle pain and muscle weakness. Physical examination of patient revealed 150/80 mmHg, upper and lower extremity muscle strength loss. Laboratory measurements showed low potassium level (1.7 mEq/l), elevated CPK level (1825 IU/l) and metabolic alkalosis. Hypokalemic periodic paralysis was suspected and after normalizing potassium level PAC and PRA were 46 ng/dl (7–30 ng/dl) and 0.3 ng/ml per h (0.7–3.3 ng/ml per h) respectively. PAC to PRA was 153.3. Primary aldosteronism was confirmed with saline infusion test. Other endocrinologic tests were normal. MRI revealed 15×9 mm adenoma in left surrenal. Spironolactone was added and left surrenalectomy was performed to the patient. Histopathologic diagnosis was adrenocortical adenoma.

Conclusion: Hypokalemia may cause proximal muscle weakness, cramps, fatigue, polyuria polydipsia, nocturia, rhabdomyolysis and hypokalemic periodic paralysis. PHA patients may be misdiagnosed with polymyositis due to high CPK levels and guillain barre syndrome due to quadriparalysis. Therefore, when patients are admitted with symptoms indicating hypokalemia, potassium levels should be measured and if hypokalemia and hypertension is observed PHA should be examined.