Developing a blood test to diagnose curable hypertension
Many people suffering from curable secondary hypertension - high blood pressure that is the result of a condition - are incorrectly diagnosed, so they don't receive the treatment they need. An EU-funded project's research aims to lead to a blood test that aids diagnosis and improves treatment.
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More than a third of the population in Europe is affected by high blood pressure, known as hypertension. It causes cardiovascular problems including stroke and heart disease, and is responsible for more than a million deaths every year.
Although there are many drugs designed to bring down high blood pressure, they don’t work for everyone. Yet around one in ten of all cases of hypertension adding up to hundreds of thousands of people could be cured if they were correctly diagnosed.
Many of these curable cases of hypertension involve disorders of the adrenal glands, and are known as curable hypertension. The adrenals sit above the kidneys and produce hormones including aldosterone, adrenaline and cortisol that increase blood pressure. Patients whose adrenal glands are overactive for example, because of a benign tumour, or for some other reason produce excessive amounts of hormones, which cause hypertension.
These conditions can be relatively simple to treat, either through drugs or surgery, which can completely cure the associated hypertension. But they are difficult and expensive to detect, and can only be diagnosed in specialist centres, so many patients miss out on an accurate diagnosis and effective treatment.
By studying thousands of hypertensive patients across Europe, the EU-funded ENSAT-HT project is searching for molecules in the bloodstream known as biomarkers that can accurately and reliably identify people who could be cured.
“In addition to increasing blood pressure, these hormones cause organ damage, they modify the blood vessels and the heart and patients have a decreased quality of life,” says the project’s scientific co-ordinator Maria-Christina Zennaro of France’s Institut national de la santé et de la recherche médicale (INSERM). “If we find a simple way to identify these patients whose hypertension is due to hormones, we can target them with more appropriate treatment and we would have much more success.”
In the blood
For the first phase of the study, 500 people have been recruited from specialist adrenal disorder centres across Europe. There are 300 patients with curable hypertension, 100 with a different form of high blood pressure, called ‘primary hypertension’, and 100 with normal blood pressure. The researchers are using cutting edge techniques to analyse blood samples in search of tell-tale molecular signals a process that should be complete by the end of 2017.
Next, the team will expand the study to include 4 000 people with various types of hypertension recruited from six major expert European centres, to see whether these biomarkers can reliably identify patients with curable hypertension.
Once the ENSAT-HT team have found suitable biomarkers, their discovery will need to be developed into a simple, reliable blood test, which must be verified in a larger, randomised trial. Then it will need to go through the appropriate steps to be developed into a clinical grade test.
To do this, the researchers have paired with Inserm Transfert the technology transfer company owned by INSERM to identify and liaise with potential commercial partners.
Zennaro hopes that such a test would enable people with curable hypertension to be quickly and accurately diagnosed an advance that could prevent many deaths and greatly improve the quality of life for affected individuals by getting the right treatment to the right patient as quickly as possible.
“The longer you have hypertension, the more your blood vessels are damaged,” she adds. “Diagnosis has to be made more rapidly, not by specialists in big regional centres but by local doctors anywhere. And if we can diagnose people, we can cure them.”