A new test

One cause of hypertension is when the adrenal glands produce too much of a hormone called aldosterone. Up to now, there has only been one test for this, and it has several limitations. But now, doctors have tested a new type of test that uses a radioactive dye to find out which patients have hypertension caused by a benign tumour that secretes too much of this hormone.


Researchers have solved a 60-year conundrum of reliably detecting nodules that produce a hypertension-causing hormone with a quick and painless test

 Hypertension can be caused or exacerbated by many different underlying issues. One such cause is when the adrenal glands produce too much of a hormone called aldosterone. This is called Conn's syndrome, and it causes the body to retain salt, which leads to high blood pressure, and a higher risk of stroke or heart attack than other forms of hypertension. In at least half of cases, this is caused by a nodule in one of the adrenal glands – but testing for this is difficult. The new test

Doctors at Queen Mary University of London, Barts Hospital, and Cambridge University Hospital, scanned 128 people with hypertension caused by aldosterone. They were able to do this by using a very short-acting dose of metomidate, a radioactive dye that sticks only to the aldosterone-producing nodule.

They found that two thirds of the participants had hypertension caused by a benign tumour that secreted elevated levels of this hormone.

For patients

The researchers hope that those who've been diagnosed with Conn's syndrome could be tested using their special CT scan, and go on to further treatment if a nodule is found on their adrenal gland. They hope that doctors will be encouraged to look for Conn's syndrome before it has caused difficult-to-treat hypertension, since the earlier it's found, the more likely it can be cured.

Morris Brown, co-senior author of the study and Professor of Endocrine Hypertension at Queen Mary University of London, said: "These aldosterone-producing nodules are very small and easily overlooked on a regular CT scan. When they glow for a few minutes after our injection, they are revealed as the obvious cause of hypertension, which can often then be cured. Until now, 99% are never diagnosed because of the difficulty and unavailability of tests. Hopefully this is about to change."