Primair hyperaldosteronisme

- Primary hyperaldosteronism (PHA), autonomic secretion of aldosterone by the adrenal gland, is rare.

- PHA usually results in therapy-resistant hypertension and is often but not always accompanied by hypokalaemia.

- Common causes of PHA are an aldosterone-producing adenoma, idiopathic aldosterone hypersecretion, unilateral hyperplasia or a genetic variant: glucocorticoid-remediable aldosteronism (GRA).

- The diagnosis should be phased and first of all requires a biochemical confirmation of the presence of PHA. In PHA patients, plasma renin is invariably suppressed. Blood should be collected under standardised conditions while the patient is not using beta-blockers or centrally-acting antihypertensive medication.

- Patients with a suppressed plasma renin and an elevated plasma aldosterone concentration have PHA. In patients with a suppressed plasma renin and a high-normal plasma aldosterone concentration a confirming test should be performed in which PHA is diagnosed if aldosterone is not suppressed following volume expansion with sodium chloride.

- The cause of PHA is determined by means of a CT scan or MRI of the adrenal glands to find a unilateral adenoma. If the CT scan or MRI is normal, adrenal vein aldosterone sampling may be considered as a next step in order to demonstrate lateralisation of aldosterone production.

- The hypertension and hypokalaemia of all forms of PHA respond well to spironolactone therapy. In the case of a unilateral adenoma or unilateral hyperplasia, adrenalectomy is the treatment of choice. For GRA, dexamethasone in doses that reduce the corticotropin (ACTH) level is indicated.