Editing Adrenal: Hyperaldosteronism (section)

==== Labs ====

* '''Aldosterone-to-renin ratio (ARR)'''
** '''Used to screen for primary hyperaldosteronism.'''
** Involves measuring a morning (between 8-10 AM) plasma aldosterone concentration (PAC) and plasma renin activity (PRA).
** An ARR of > 20 (some suggest > 30) along with a concomitant aldosterone concentration > 15 ng/mL is indicative of hyperaldosteronism; standard thresholds have not been established due to laboratory variability.
* '''Before screening is initiated, hypokalemia should be corrected and all contraindicated medications discontinued'''.
** Although patients can continue the majority of anti-hypertensive agents during screening, '''potassium-sparing diuretics such as amiloride or triamterene, and especially mineralocorticoid receptor blockers such as spironolactone and eplerenone, alter the RAAS and will affect test results. These medications should be stopped approximately 6 weeks before testing.'''
* 50-70% of patients with a positive screening test will be diagnosed with primary aldosteronism following confirmatory testing. '''The majority of confirmatory tests evaluate the suppression of aldosterone after sodium loading.'''
** The underlying theory behind the sodium loading tests is that loading will decrease plasma renin and aldosterone production in patients without autonomous aldosterone secretion.
*** The oral sodium loading test is conducted by administering a high-sodium diet for 3 days, followed by 24-hour urine measurements of aldosterone, sodium, and creatinine.