Scientists shed new light on cause of high blood pressure
Researchers in the UK say they can detect a common cause of high blood pressure thanks to a pioneering 10-minute scan. Scientists claim the CT scan can light up hormone producing nodules which can cause hypertension, also known as high blood pressure, a condition that requires life-long treatment and the cause of which is often unknown.
The nodules, or growths, glow shortly after an injection is given and highlight an obvious cause for the condition, the scientists say.
A total of 128 people participated in the study of a new scan after doctors found that their condition was caused by a steroid hormone called aldosterone.
Aldosterone causes salt to be retained in the body, driving up blood pressure. Patients with excessive aldosterone levels in the blood are resistant to treatment with commonly used drugs for hypertension, and at increased risk of heart attack and stroke.
The research also found that, when combined with a urine test, the scan detects a group of patients who come off their blood pressure medicine after treatment.
The scan found that in two thirds of patients with elevated aldosterone secretion, it is caused by a benign nodule in one of the adrenal glands, which can then be safely removed.
Until now, the catheter test was unable to predict which patients would be cured of hypertension by surgical removal of the gland. By contrast, the combination of a ‘hot nodule’ on the scan and urine steroid test detected 18 of the 24 patients who achieved normal blood pressure off all their drugs.
The research, published in Nature Medicine, was conducted on patients at St Barts, Guy’s and St Thomas’s hospitals in London, Cambridge University Hospital and the universities of Glasgow and Birmingham. It was funded by the National Institute for Health and Care Research and Medical Research Council partnership, Barts Charity and the British Heart Foundation.
Morris Brown, co-senior author of the study and professor of endocrine hypertension at Queen Mary University in 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 per cent are never diagnosed because of the difficulty and unavailability of tests. Hopefully this is about to change.” Previous research by the group at Queen Mary University discovered that in 5 to 10 per cent of people with hypertension, the cause was a gene mutation in the adrenal glands, which resulted in excessive amounts of aldosterone being produced.