Protein that fuels diabetes and high blood pressure identified by scientists

By Mark Waghorn via SWNS

A protein that fuels high blood pressure and diabetes has been identified by scientists, explaining the link between the two.

It shows why the potentially deadly conditions often go hand in hand - opening the door to the development of better therapies.

Senior author Professor Julian Paton, of the University of Auckland, said: "We have known for a long time hypertension and diabetes are inextricably linked.

"We have finally discovered the reason, which will now inform new treatment strategies."

Most people with diabetes will eventually have high blood pressure, or hypertension, along with other heart and circulatory problems.

This can lead to many complications, including eye and kidney disease, or make them worse.

The protein, called GLP-1 (glucagon-like peptide-1), is released from the wall of the gut after eating.

It triggers the glucose-controlling hormone insulin from the pancreas - and also boosts the carotid body in the throat.

The tiny organ is extremely sensitive to oxygen - helping to regulate blood pressure.

Experiments in rats found the receptor that senses GLP-1 was less effective in those with high blood pressure.

A state-of-the-art scanning technique called RNA sequencing read all the messages of expressed genes in the carotid body.

Senior author Prof David Murphy, of the University of Bristol, explained: "Locating the link required genetic profiling and multiple steps of validation.

"We never expected to see GLP-1 come up on the radar. This is very exciting and opens many new opportunities."

More than 37 million Americans have diabetes (about 1 in 10), and approximately 90-95% of them have type 2 diabetes, which is linked to an unhealthy lifestyle.

Nearly half of adults in the United States (47%, or 116 million) have hypertension, according to the CDC.

Many people go undiagnosed, as there are no symptoms. The 'silent killer' can cause heart attacks and strokes.

Prof Paton said: "The carotid body is the convergent point where GLP-1 acts to control both blood sugar and blood pressure simultaneously.

"This is coordinated by the nervous system which is instructed by the carotid body."

People with hypertension, diabetes, or both, are at high risk of life-threatening cardiovascular disease

This remains the case for a large number of patients - even when receiving medications. Most drugs only treat the symptoms, and not the cause.

Drugs containing GLP-1could lower blood sugar and blood pressure - simultaneously.

It would target the root cause of the illnesses - rather than just the symptoms.

Professor Rod Jackson, a world-renowned epidemiologist from Auckland, New Zealand, said: "We have known blood pressure is notoriously difficult to control in patients with high blood sugar.

"So these findings are really important because by giving GLP-1 we might be able to reduce both sugar and pressure together, and these two factors are major contributors to cardiovascular risk."

Lead author Audrys Pauza, a student in Prof Murphy's lab added: "The prevalence of diabetes and hypertension is increasing throughout the world, and there is an urgent need to address this.

"Drugs targeting the GLP-1 receptor are already approved for use in humans and widely used to treat diabetes.

"Besides helping to lower blood sugar these drugs also reduce blood pressure. However, the mechanism of this effect was not well understood.

"This research revealed these drugs may actually work on the carotid bodies to enact their anti-hypertensive effect.

"Leading from this work, we are already planning translational studies in humans to bring this discovery into practice so patients most at risk can receive the best treatment available."

The research has also revealed many other new targets for ongoing functional studies.

It is hoped they will lead to future translational projects in hypertensive and diabetic patients.

The study, funded by the British Heart Foundation and the Health Research Council of New Zealand, is in Circulation Research.