Primary Aldosteronism Much More Prevalent Than Previously Thought

Up to 60% of patients with resistant hypertension may be impacted

With David Weiner MD

 

People who have the condition have a mortality rate 90% higher than their counterparts. That risk, when aldosteronism is identified and treated, almost completely disappears.

If you ask a primary care doctor about primary aldosteronism, most would say it is a very rare condition, and few would say they had seen a case in practice. However, a new study has found as many as 60% of those with resistant hypertension, and more than 11% of the general population may have the condition.

Primary aldosteronism is a condition in which there is excess secretion of aldosterone, and suppression of renin. This can lead to complications ranging from excessively high blood pressure that isn’t controlled with the usual drugs and lifestyle changes, cardiovascular disease, strokes at a young age, and problems with potassium levels. It can also make diabetes more difficult to control.

Other studies have estimated a prevalence of the condition at between 5 and 10%, however, there is a lack of testing for the condition among patients who may be at risk for the disease or already unknowingly experiencing it. Subsequent testing to confirm the condition after initial tests suggests that it should be considered expansive and invasive.

Study details

In the study, Jennifer M. Brown, MD, and her colleagues looked at data from more than 1,000 patients at 4 academic medical centers:

  • They were divided into groups that had normal blood pressure, stage 1 hypertension, stage 2 hypertension, and resistant hypertension.
  •  Patients already on anti-hypertensive drugs had them withdrawn over a period of 2 weeks to 3 months.
  • They were prescribed a high sodium diet with normal potassium levels for five to seven days before testing.
  • They took an oral sodium suppression test, one of the current confirmatory tests used to diagnose primary aldosteronism.
  • Those with high sodium levels and suppressed renin were also given a urine test to determine aldosterone levels.
  • Those who had levels higher than 12 μg/24 h were given a diagnosis of primary aldosteronism.

Results

The researchers found that 11.3% of those with normal blood pressure, and 22% of those with resistant hypertension had levels of aldosterone that confirmed primary aldosteronism. The severity of aldosteronism paralleled the degree of hypertension. They also noted that there is an arbitrary nature to the current recommendations regarding diagnosis. “Among participants with resistant hypertension, where the pretest probability of primary aldosteronism is high, 24.5% of confirmed case patients (24 of 98) had a serum aldosterone concentration less than 277 pmol/L (10 ng/dL), a threshold below which the diagnosis of primary aldosteronism is almost never entertained.”

Despite the fact that so many consider it a rare condition, the authors note that “it is frequently identified when hypertensive persons undergo systematic screening for a high ARR and aldosterone level.” They further note under-diagnosis is partly related to current recommendations for aldosterone levels required for diagnosis, and that primary aldosteronism may well be a primary reason for hypertension, rather than the opposite. Using current recommendations, they would have missed up to 25% of the patients they diagnosed with primary aldosteronism.

Discussion

David Weiner MD, a professor of medicine, physiology, and functional genomics at the University of Florida, says he sees three to four patients with primary aldosteronism a week in his practice. “There have been hints in the literature that it’s more prevalent that people thought, and I think about this all the time, so the results didn’t surprise me.”

The dangers of not recognizing the problem are threefold, Weiner says. “It can lead to high blood pressure that is hard to control, with all the potential dangers that untreated high blood pressure brings with it,” he notes. He has had patients in his practice who were on five different blood pressure medications, but still could not bring their condition under control.

Second, patients may also have issues with low potassium levels – although Weiner says this is less common. This can lead to heart arrhythmias that may be severe and increase the risk of cardiac death. It can also create problems controlling diabetes.

Lastly, compared to patients who don’t have primary aldosteronism – even when adjusting for everything including high blood pressure – people who have the condition have a mortality rate 90% higher than their counterparts. That risk, when aldosteronism is identified and treated, almost completely disappears, he says.

As the authors note, Weiner says there are some issues related to appropriate testing to determine whether a patient has primary aldosteronism, but there have been advances in that, as well. A study released this spring provides a decision-making tool to help physicians determine who should be tested.  A second study evaluated the current testing methods.

Treatments

Once detected, Weiner says there are two ways to treat primary aldosteronism. First, a physician needs to determine if one or both adrenal glands are misbehaving using a catheterization procedure analogous to heart catheterizations. If just a single gland is abnormal, then laparoscopic surgery to remove the faulty gland solves the problem.

The second is medication which blocks the effects of excess aldosterone. These can have side effects including menstrual irregularities in women and breast growth and pain in men. In both genders it can lead to decreased libido. However, Weiner says that most people tolerate the medication with little or no side effects, and they are dose dependent: those who are on lower doses are less likely to experience them.

What treatment is chosen is highly subjective, he says. For example, a patient older than 70 may decide that surgery isn’t a good choice. But in a younger patient, avoiding a lifetime of medications that could impact their body image or reproductive health could tip the scales in favor of surgery.

Weiner would like to see primary care physicians look for primary aldosteronism in their patients with high blood pressure that has been difficult to control. If they have such patients, “do the initial screening to measure aldosterone and renin.” While it may not be beneficial to go looking for it in everyone, for those with uncontrolled or difficult to control high blood pressure it makes sense.

There is still work to be done about the impact on those with normal or low blood pressure, says Weiner. “This paper found that it existed even in those populations, but we just don’t know yet whether it makes sense to test for it and then treat it in those patients, whether it would improve mortality.”

This won’t change much in Weiner’s practice, but he appreciates the authors and their efforts to raise awareness among the wider medical community that this condition isn’t well known, is thought rare, and thus leaves many untreated and at almost double the risk of death as those without primary aldosteronism.

He concludes with a story about his time at Washington University of St. Louis, where in three years, he didn’t see a single patient with a known aldosteronism diagnosis. “I don’t think the biology of people has changed. I think our awareness has.”

Continue Reading:
Many Patients with Essential Hypertension Have Stress-Induced Aldosterone Hypersecretion
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