Diagnosis and Management of Primary Aldosteronism and Liddle Syndrome

Underlying Pathophysiology

Conn's syndrome is caused by autonomous aldosterone overproduction from either an adrenal adenoma or bilateral adrenal hyperplasia, leading to sodium retention and potassium excretion in the distal nephron, as recommended by the National Comprehensive Cancer Network 3, 4
Liddle syndrome results from genetic mutations in the epithelial sodium channel (ENaC) subunits, causing excessive sodium channels to remain in the cell membrane and increasing sodium reabsorption, according to the American Academy of Pediatrics 1, 2, 6

Both conditions often present with hypertension, hypokalemia, and metabolic alkalosis, as noted by the European Heart Journal 3, 5
Liddle syndrome typically presents in childhood or adolescence, whereas Conn's syndrome presents in the fourth to fifth decade, as reported in Pediatrics 2

Conn's syndrome is characterized by elevated plasma aldosterone concentration, suppressed plasma renin activity, and an aldosterone-to-renin ratio typically >30, as recommended by the National Comprehensive Cancer Network 3, 4, 5
Liddle syndrome is characterized by suppressed plasma aldosterone levels, suppressed plasma renin activity, and low aldosterone and renin levels, as noted by the American Academy of Pediatrics 2

For Conn's syndrome, laparoscopic adrenalectomy is the treatment of choice for unilateral disease, and spironolactone or eplerenone can be used for bilateral disease or non-surgical candidates, as recommended by the National Comprehensive Cancer Network 3, 4, 7
For Liddle syndrome, amiloride or triamterene can be used to directly block ENaC channels, and a low sodium diet is essential, as reported in the medical literature 2

Measuring both aldosterone and renin is crucial when evaluating mineralocorticoid hypertension, as measuring only one can lead to misdiagnosis, as noted by the National Comprehensive Cancer Network 3
Genetic testing for Liddle syndrome should be considered in young patients with hypertension, suppressed renin and aldosterone, and a family history, as recommended by the American Academy of Pediatrics 2