Last week the Annals of Internal Medicine published a cross-sectional study on the prevalence of primary aldosteronism (PA).
The study examined urine aldosterone levels in 4 groups of patients (normotension, stage 1 HTN, stage 2 HTN, and resistant HTN) after they received an oral sodium suppression test, which is a confirmatory test in the work-up of primary aldosteronism. The study found that the prevalence of PA ranged from 11% in the normotensive group to 22% in the resistant HTN group. These numbers were 3-5x that found with the aldosterone-renin ratio (ARR), the traditional screening test for PA.
What implications does this study have?
First, it suggests that PA is even more underdiagnosed than we thought.
Second, PA can affect patients of any BP category (even in normotension!) As such, we should consider screening for PA much more frequently than we currently do (especially in the general hypertensive population).
Third, a single ARR is an insensitive (and potentially misleading) screening test for PA. Thus a plasma renin concentration may be the best initial test, but more studies are needed.
Last, in an editorial response, the lead author of the 2016 Endocrine Society’s clinical practice guideline for managing PA calls the above study “a game changer” and says that much of the Endocrine Society’s “guideline needs to be jettisoned, and radically reconstructed recommendations should be developed to guide clinicians in treating hypertensive patients.”