michigan hypertension core curriculum - State of Michigan

Definition
Prevalence
Clinical Features
Diagnosis
Types of Pathology
Evaluation and Therapy
98 Hypertension Core Curriculum
Primary Aldosteronism
Susan Steigerwalt, MD
Pre test questions:
1) What are the characteristics of hypertensive patients who should be screened for primary
aldosteronism (PA)?
2) What are the mechanisms for high BP in PA?
3) What is the recommended screening test for PA? What is the role for confirmatory testing?
Primary aldosteronism (PA) is a syndrome resulting from the autonomous hyper secretion of
aldosterone that is non suppressible by sodium loading. Aldosterone (aldo) is produced by a solitary
adenoma or hyperplasia, or a combination of the two. The excess aldosterone results in cardiovascular
hypertrophy and fibrosis as well as proteinuria most prominently when there is high dietary consumption
of sodium. Other metabolic perturbations in the setting of high circulating aldosterone levels include
an increase in plasminogen activator inhibitor 1 (PAI-1) associated with increased thrombosis and
hypertension that may be, though not invariably, accompanied by hypokalemia, metabolic alkalosis,
mild hypernatremia and glucose intolerance. Patient with PA have higher cardiovascular morbidity
and mortality than age and sex-matched patients with primary hypertension. Thus, it is important
to diagnose when it is present as there are specific treatments such as use of thiazide diuretics to
control the aldosterone-induced volume expansion and aldosterone antagonists (spironolactone and
epleronone) to specifically antagonize elevated circulating aldosterone levels and also the removal of
solitary adrenal glands when hypersecretion of aldosterone can be localized to one adrenal gland.
Primary aldosteronism occurs in about 20% of patients with resistant hypertension (BP above goal
despite therapeutic doses of three antihypertensive medications, including a diuretic or controlled BP
on at least 4 BP lowering medications) and up to 10% of unselected hypertensive populations.