GPs take a second look at primary aldosteronism and high blood pressure

A simple blood test for primary aldosteronism could save more than half a million Australians from unnecessary illness, medication and expense, a new study has found.

The Australian-first study led by Hudson Institute of Medical Research, to be published in the Medical Journal of Australia, found that of the one-in-three Australian adults with high blood pressure, at least ten percent have the adrenal disease primary aldosteronism (PA). This equates to approximately 600,000 people in Australia.

Stroke, heart attack, kidney risk

In people with PA the adrenal glands produce too much aldosterone, a salt retaining hormone. As well as high blood pressure, PA increases the risk of stroke, heart attack and kidney disease, but it is rarely diagnosed. Yet, if it is accurately diagnosed, PA can be cured or effectively treated using a simple medication.

Consultant Endocrinologist, Dr Jun Yang heads the Endocrine Hypertension Research group at Hudson Institute of Medical Research. Her team, including first author of the study, PhD student Renata Libianto, asked 70 General Practitioners to test patients with high blood pressure for PA, and the results were astounding.

“Before the study these GPs reported less than one in every thousand of their patients having PA, but once they started testing for it, the figure jumped to 14 per cent,” Dr Yang said.

“People with high blood pressure are often prescribed a range of medications to manage it, but if PA is the cause, those medicines won’t help the condition and may even be harmful to their health. So, it is vital that these patients are tested for PA.”

GP Dr Edward Tsui was part of the study, and surprised to see four out of the first 13 people he screened (and six out of 60 in all) being diagnosed with PA.

“Findings suggesting one in seven people with newly diagnosed hypertension could have PA would be a very significant reason for GPs to screen for the condition, and should prompt a review of the current guidelines for initial hypertension management,” Dr Tsui said.

“Knowing that early detection and treatment of PA can reduce the long-term risk of significant hypertensive complications has been extremely satisfying. The simplicity of a blood test, and the potential to effectively treat the condition with a single medication in most cases has the potential to massively reduce the burden of disease on the patient and financial costs to the community.”

Never heard of primary aldosteronism

David Wyatt knew he had high blood pressure for many years but like most Australians, had never heard of PA.

“I was diagnosed with high blood pressure (BP) over 15 years ago and told that the cause was unknown and I would remain on medications for the rest of my life. The BP caused other health effects such as bleeding behind the eye and thickening of the heart walls. After a lot of (nervous) experimentation I ended up on three medications,” Mr Wyatt said.

“A couple of years ago I developed arrythmia and ended up in hospital. Someone referred me (without my knowledge) to Dr Yang at Hudson Institute who quickly diagnosed PA. As this was treated my blood pressure dropped and is now on the low end of normal.

“I had never heard of PA before and I consider myself lucky that I was admitted to the one hospital that had Hudson Institute attached to it.”

Dr Yang says greater knowledge of PA and more testing when patients first show signs of high blood pressure will improve many people’s health and quality of life.

“It also makes sense financially, as effective treatment of PA will cut the costs of unnecessary medications, preventable heart disease and premature deaths,” she said.

Dr Jun Yang explains more about high blood pressure and primary aldosteronism with Dr Norman Swan on the ABC Health Report

“One of the reasons that really drove me to pursue this line of research because in the current guidelines, primary aldosteronism tends to be portrayed as an afterthought, as; if all else fails then think about an underlying cause for the high blood pressure, if it’s really hard to control despite full medications, then think about it.

But by that stage, patients have often had high blood pressure for many decades and they have probably already suffered damage that could have been prevented if we test for it early, which is why we did this research and we asked GPs to test for primary aldosteronism in patients who have not yet been started on medications.” – Dr Jun Yang