Primary hyperaldosteronism by autonomous overproduction of aldosterone from adrenal cortex caused by an adrenal adenoma, despite a high pressure with low renin activity
Conn's Syndrome
80% are from solitary adenoma, the rest are from bilateral hyperplasia
Rarely malignant
Secondary Hypertension
Mostly under age 30 or above age 60 and hypertension is not controlled by 3 antihypertensive medications (5 to 10% of all HTN)
Clinical features of Conn's Syndrome
Hypokalemia leads to muscle weakness or diabetes insipidus (polyuria & nocturnal polyuria)
Metabolic alkalosis is common
HIGH BP + HYPOKALEMIA
Primary hyperaldosteronism (CONN'S)
Investigations for Conn's Syndrome
1. Plasma aldosterone: renin ratio (ARB) as best initial screening test
2. Plasma renin - low levels
3. Normal saline infusion test as most accurate test
Hypokalemia often present but normal potassium does not exclude the diagnosis
Urinary potassium loss greater than 30 mmol daily during hypokalemia
Imaging for Conn's Syndrome
CT or MRI of adrenals done after hyperaldosteronism is established to differentiate adenoma from hyperplasia
Management of Conn's Syndrome
1. Surgical removal of the unilateral adenoma
2. Bilateral hyperplasia and patients who cannot have surgery are treated with eplerenone or spironolactone
