A simple blood test could detect primary aldosteronism, a common cause of high blood pressure

Could a simple blood test lead to a cure for a type of blood pressure? Researchers say it could be key for around 600,000 Australians.

A common cause of high blood pressure that affects around 600,000 Australians can be detected by a simple blood test that for some may lead to a cure of the “silent killer”.

The key, say Victorian researchers, will be to get GPs to order the blood test to screen for primary aldosteronism (PA) when patients present with hypertension.

One in three adults in Australia have high blood pressure and research suggests in around 10 per cent the cause is PA.

This is a disease where the adrenal glands produce too much of the hormone aldosterone that controls sodium and potassium levels in the blood. Aldosterone also regulates the health of the heart, kidneys and blood vessels.

While easily treated with a cheap and readily available daily aldosterone-blocking pill or potentially cured with keyhole surgery if the root cause is a small tumour on the adrenal gland, many GPs have been taught the disease is rare. Consequently, many doctors do not routinely check for PA in patients with high blood pressure.

The blood test is a game-changer, says Associate Professor Jun Yang, an endocrinologist and researcher at the Hudson Institute of Medical Research, Monash University and Monash Health, who says PA is not only common, but much more harmful to the heart, brain and kidneys than other types of high blood pressure.

Last year A/Prof Yang and her PhD student, Dr Renata Libianto, led the research published in the Medical Journal of Australia that called for nationwide screening for this “silent killer”.

The authors said the study suggested PA was much more frequent than previously recognised and highlighted the central role of GPs in its early detection.

A/Prof Yang is now preparing to recruit GPs at primary care clinics for a randomised study across Victoria, South Australia and Tasmania that she hopes will eventually lead to screening all Australians with high blood pressure for the disease.

“The GPs in the study will have software added to their clinics’ already existing computer programs,” A/Prof Yang said. “This software will prompt some with a button that automatically brings up the PA blood test request when treating a patient with high blood pressure.

“We will then study the patient outcomes comparing when doctors screen for the disease with those who do not.”

Associate Professor Jun Yang and her father Lisheng, who now takes a quarter of a tablet that controls his blood pressure “perfectly". Supplied.

A/Prof Yang’s parents were both diagnosed and treated for PA after she started researching the disease. Her father Lisheng had been on four daily drugs and was still struggling to control his blood pressure. Following confirmation of PA he is now on a quarter of one tablet that controls his blood pressure “perfectly”, as is her mother, Professor Cherrie Zhu.

“There are not many things in life that can be cured,” A/Prof Yang said. “But identifying PA means we can treat the root cause of the disease.

Associate Professor Jun Yang with her parents, father Lisheng and mother Professor Cherrie Zhu. Both were diagnosed with PA after she started researching the disease. Supplied.

“We know that around 30 per cent of people with PA might have a tumour that can be removed by surgery and their high blood pressure is then cured.”

A/Prof Yang is urging people with high blood pressure to have the blood test, particularly those patients whose blood pressure is not well controlled by medication.

“PA ticks all the boxes for diseases that should be screened,” she said. “There is a drug to treat it that we know works.”

Melbourne GP Dr John Malios discovered his high blood pressure was caused by PA about five years ago.

“(As GPs) we were always taught this was a rare condition,” he said. “It is not rare.”

Dr Malios said his own diagnosis was made after a young doctor noticed his potassium level was low and encouraged him to follow up on it.

“In 50 years of general practice I saw lots of patients with hypertension, ironically where we had a case where it was hard to control, we added an aldosterone-blocking drug and that worked.”

Where Dr Malios had been on a number of medications to control his high blood pressure, he said following the diagnosis and taking aldosterone-blocking medication, his disease is now under control.

“When you see something that stops a disease completely, and you have such a good effect on blood pressure, it is life-changing.”

Fast facts:

• Around one in 10 people with high blood pressure may have primary aldosteronism

• It is treatable with readily available drugs or surgery, depending on the cause

• Up to 600,000 Australians may be living with PA without knowing it, putting them at risk of stroke, heart disease and reduced kidney function

Originally published as A simple blood test could detect primary aldosteronism, a common cause of high blood pressure