Understanding the causes of high blood pressure in young adults

Investigating the role of the carotid body in young onset hypertension (Dr Thomas Hinton)

The number of young adults (aged 18-40 years) with high blood pressure, known as hypertension, is rising. This is worrying because high blood pressure is a leading cause of heart and circulatory disease. It is not clear why young people get hypertension, but an increase in what is called the ‘sympathetic’ arm of the nervous system is thought to be important. This nervous system can be controlled by small organs called ‘carotid bodies’ located close to the main blood vessels carrying blood to the brain. Dr Emma Hart’s lab has shown that carotid bodies increase blood pressure, in animals and in a study of older people. In this fellowship, a Clinical Research Training Fellow working with Dr Hart is using a drug called dopamine to block the activity of carotid bodies at rest and during exercise in young people with high blood pressure to see if this lowers breathing rates, blood pressure and sympathetic nerve activity. They will also look at how sensitive the participants are to low levels of oxygen compared to people of the same age with normal blood pressure. Dr Hart hopes to determine whether the carotid body is overactive in young people with high blood pressure before they start medication, and whether it contributes to the blood pressure increase seen after exercise. If this is the case, it would reveal a new way to control blood pressure in young people.