People with hypertension and/or diabetes are at high risk of life-threatening cardiovascular disease. Even when receiving medication, a large number of patients will remain at high risk. The long-standing question of why so many patients suffering with hypertension also have diabetes has been answered by an international team led by the University of Bristol in the U.K. and the University of Auckland in New Zealand.

The researchers have demonstrated that a small protein cell glucagon-like peptide-1 (GLP-1) couples the body’s control of blood sugar and blood pressure.

Their findings are published in the journal Circulation Research in a paper titled, “GLP1R Attenuates Sympathetic Response to High Glucose via Carotid Body Inhibition.”

“Aberrant sympathetic nerve activity exacerbates cardiovascular risk in hypertension and diabetes, which are common comorbidities, yet clinically sympathetic nerve activity remains poorly controlled,” noted the researchers. “The hypertensive diabetic state is associated with increased reflex sensitivity and tonic drive from the peripheral chemoreceptors, the cause of which is unknown.”

“We’ve known for a long time that hypertension and diabetes are inextricably linked and have finally discovered the reason, which will now inform new treatment strategies,” explained Julian Paton, a senior author, and director of Manaaki Mānawa Centre for Heart Research at the University of Auckland.

The University of Bristol group used RNA sequencing to read all the messages of the expressed genes in the carotid body in rats with and without high blood pressure.

David Murphy, PhD, professor of experimental medicine from Bristol Medical School: Translational Health Sciences (THS) and senior author, added: “Locating the link required genetic profiling and multiple steps of validation. We never expected to see GLP-1 come up on the radar, so this is very exciting and opens many new opportunities.”

Revealing GLP-1 is just the start for the researchers. The findings have revealed many novel targets for ongoing functional studies that the team anticipate will lead to future translational projects in human hypertensive and diabetic patients.