Hypokalemia-induced rhabdomyolysis as the first symptom of primary aldosteronism: a case report and literature review

Abstract

Primary aldosteronism (PA) is a well-documented cause of secondary hypertension, often accompanied by hypokalemia. However, PA with normal blood pressure and hypokalemic rhabdomyolysis (RM) is rare. We report a case of hypokalemia-induced RM as the first symptom of PA. A 65-year-old woman was admitted due to intermittent limb weakness and myalgia. She denied a history of hypertension.Laboratory findings showed profound hypokalemia (1.8 mmol/L) and extreme elevation of creatinine kinase (CK) levels (18,370 U/L), suggestive of hypokalemia-induced RM. She was administered intravenous fluids as well as active oral and intravenous potassium supplements. CK and myoglobin levels gradually decreased, but the serum potassium recovery was poor. Further evaluations strongly suggested PA by an aldosteroneproducing adenoma, which was surgically removed. After surgery, the patient recovered well. The systolic blood pressure decreased by approximately 10-20 mmHg and the diastolic blood pressure decreased by approximately 5-10 mmHg. After discontinuation of spironolactone and oral potassium supplementation, the patient had normal serum potassium levels. This case indicates that PA is a cause of hypokalemic RM, even in patients with normal blood pressure. In addition, attention should be paid to changes in serum aminotransferase levels associated with RM. If the patient had no liver disease, it might be a marker for skeletal muscle injury instead of hepatocyte damage.

Should we suspect primary aldosteronism in patients with hypokalaemic rhabdomyolysis? A systematic review

“…All 13 patients had a history of hypertension and weakness and/or myalgias. Twelve out of 13 patients had blood potassium lower than 2.5 mmol/L, 11 had adrenal adenoma, and none had renal failure ( 8 ). In a review of the English literature, 22 cases of PA related to hypokalaemic RML were summarised.…”

“…RML has been described in patients with electrolyte disorders and endocrine disorders such as hypothyroidism and hyperthyroidism, hyperaldosteronism, diabetes mellitus, and diabetic ketoacidosis ( 4 ). One of the most intriguing causes of RML is potassium deficiency ( 8 ). The mechanism of hypokalaemia-induced RML is still not clear.…”