Hyperaldosteronism, also known as Conn syndrome, is the most common cause of secondary hypertension, accounting for 5-13% of cases. It is characterized by hypokalemia in around half of patients with aldosterone-producing adenomas and 17% of patients with bilateral hyperplasia. Diagnosis involves measuring plasma renin activity and plasma aldosterone concentration along with confirmation tests such as saline loading, saline infusion, or fludrocortisone suppression. Adrenal vein sampling may be used if surgical treatment is an option to determine if hyperaldosteronism is unilateral or bilateral.

1. Hyperaldosteronism
AKA Conn Syndrome
Houghton 3/26

4. Hyperaldosteronism
• Most common cause of secondary hypertension (5-13%)
• DDx includes: Cushing's syndrome, licorice ingestion,
certain forms of congenital adrenal hyperplasia, Liddle's
syndrome, and rare renin-secreting tumors
• Hypokalemia
– 50% of patients with aldosterone-producing adenomas
– 17 % of patients with bilateral hyperplasia
Clin Endocrinol (Oxf). 2007;66(5):607.

6. Measuring PRA and PAC
• Simultaneous morning measurement (8am)
• ?Antihypertensives
– Beta-antagonists, diuretics, CCB’s: OK
– ACEI and ARBS: can lead to false negatives
– Eplerenone and spironolactone: NO

7. Confirmation of Diagnosis
• Sodium Loading
– 3 day load (5000mg daily diet or 1g salt tabs bid)
• daily potassium levels and repletion
• 24 hr urine collection on 3rd
day (aldosterone, sodium, creatinine)
• Positive if urine Na >200 and aldosterone >12mcg
– Saline Infusion
• 2 liters over 4 hours
• Measurement of serum aldosterone
• Positive if >10ng/dl
• Fludrocortisone suppression test
• Captopril challenge

8. Clinical Guidelines Subcommittee (CGS) of The
Endocrine Society for Detection of Hyperaldosteronism
• Hypertension and spontaneous or low dose diuretic-induced
hypokalemia
• Severe hypertension (>160 mmHg systolic or >100 mmHg diastolic)
or drug-resistant hypertension (defined as suboptimally-controlled
hypertension on a three-drug program that includes an adrenergic
inhibitor, vasodilator, and diuretic)
• Hypertension with adrenal incidentaloma
• Hypertension and a family history of early-onset hypertension or
cerebrovascular accident at a young age (<40 years)
• All hypertensive first-degree relatives of patients with primary
aldosteronism
J Clin Endocrinol Metab. 2008;93(9):3266.

11. Adrenal Vein Sampling
• If surgical management an option and CT scan is
normal, shows bilateral abnormalities, or shows a
unilateral abnormality but the patient is over age
40
• Usually performed with continuous cosyntropin
infusion
• Aldosterone and cortisol concentrations are
measured in the blood from three sites (right
adrenal vein, left adrenal vein, and IVC