Instant insights: Rethinking Primary Aldosteronism Diagnosis

Instant insights: Rethinking Primary Aldosteronism Diagnosis

[00:00:00] Welcome to Healthier World with Quest Diagnostics. Our goal is to prompt action from insight as we keep you up to date on current clinical and diagnostic topics in cardiovascular, metabolic, endocrine, and wellness medicine.

Maeson: Welcome to a special episode series called Instant Insights, a podcast episode designed to give you quick and highly impactful clinical pearls in just a few minutes.

Today we're dusting off your knowledge of primary aldosterone and flipping the script on the classical approach. So let's dive in. If you're a provider listening in today, you know that hypertension is one of the most common challenges in your daily practice.

What if I told you that 30% of hypertensive cases are due to primary aldosterone? And recognizing it can not only change the way that those hypertensive patients are managed, potentially getting them off multiple medications,

[00:01:00] but also reshape how you view their risk for conditions like cardiovascular, metabolic and renal disease, since PA has an elevated risk for these conditions, even compared to those with hypertension alone, primary aldosterone is considered a condition that impacts the adrenal glands, a gland that releases a hormone called aldosterone. Under normal circumstances, renin is released from the kidneys to signal for aldosterone to be secreted from the adrenals, which in turn tells our kidneys to take in potassium out of the blood for excretion in the urine.

And push out sodium and water into the blood, which naturally raises our blood volume and increases our blood pressure. So high renin signal should mean high aldosterone signal, which increases our blood volume and subsequently increases our blood pressure.

And this is a feedback loop. So low renin means low aldosterone and signals for the kidneys to stop shoving so much water and sodium into the blood so that our blood pressure doesn't continue to rise.

[00:02:00] However, in a patient with primary aldosterone adrenals produce high amounts of aldosterone even in the absence of run and signal.

Because of the high aldosterone, the kidneys continue to increase blood volume and the cycle of high blood pressure continues. so in primary aldosterone is you can expect high aldosterone, low renin, and high blood pressure.

Unfortunately, tools to identify PA have fallen short Leading providers to believe that this condition affects very few individuals with high blood pressure. Fewer than 1% of patients are even being screened for PA

The traditional screening method was called the aldosterone renin ratio, or the ARR. And this test has specific criteria for patient preparation, which requires withholding certain medications, and most importantly, the performance of the ARR varies widely with some studies showing sensitivity Below 50%. (soften language, more specific to ARR more detailed work up.)

Research from Quest Diagnostics highlights that primary [00:03:00] aldosterone evaluation based on plasma rein activity. Suppression is a better index of primary aldosterone status than the ARR. Keep in mind, primary aldosterone is characterized by low plasma renin and high aldosterone.  So first we kick this methodology off with looking at suppressed renin. A low renin level can be the first and strongest signal  pointing toward primary aldosterone is. Additionally, renin is suppressed by aldosterone itself, so if renin is low in a hypertensive patient, it's a red flag regardless of their aldosterone level.

Once suppressed, renin is confirmed. The next step is to assess whether or not aldosterone is inappropriately elevated for the suppressed rein. This confirms primary aldosterone is. (so in order to accurately reflect PA, a patient should) So here's what to expect in a patient who has been assessed for PA using this new method.

One, start with plasma rein activity. If you notice that a patient has plasma renin activity, less than one nanogram per milliliter per hour.

[00:04:00] This is considered suppressed rein. Step two, look at the plasma aldosterone concentration to assess where that patient falls along the continuum of primary aldosterone.

If their plasma aldosterone is less than five nanograms per deciliter, that's considered low renin hypertension. If a patient's aldosterone falls between five and 15 nanograms per deciliter, that's considered a positive screen for PA and less proven otherwise.

And finally, if a person's aldosterone is greater than 15 nanograms per deciliter. This is considered overt positive screening. Our research shows that this methodology identifies more than 45% of patients with renin related complications, either low renin hypertension or primary aldosterone, versus the 13.9% of patients who would've been identified using the  ARR alone.

Maeson (2): Also note that if your patient is already taking a mineral lo corticoid receptor antagonist, [00:05:00] they should withhold that medication for four to six weeks prior to checking the plasma rein activity level. Let's walk through an example comparing these two methodologies. Say you have a patient with resistant hypertension and you decide to screen them for primary aldosterone, their plasma rein comes back at 0.8 nanograms per milliliter per hour while their aldosterone comes back at 16 nanograms per deciliter.

Using the ARR, their ratio would equal 20, and this patient would not be diagnosed with primary aldosterone. However, assessing this patient for PA, using the stepwise approach, their plasma renin activity is considered suppressed less than one nanogram per mL per hour, while their aldosterone categorizes this patient as having overt primary aldosterone.

Using this new methodology we're able to identify with greater sensitivity. Those patients who suffer from primary aldosterone.

Early detection of primary aldosterone is matters. [00:06:00] Untreated PA can lead to worsened cardiometabolic conditions than primary aldosterone alone.

If you'd like to dive deeper into this research with me, you can find the links to other primary aldosterone and podcasts in the show notes. Thank you.

That's a wrap on this episode of Healthier World with Quest Diagnostics. Please follow us on your favorite podcast app and be sure to check out Quest Diagnostics Clinical Education Center for more resources, including educational webinars and research publications.

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