Nerves a key to high blood pressure

Nerves a key to high blood pressure

Helping doctors to identify which patients are more at risk of cardiovascular disease and stroke is at the heart of research being carried out by Dr Carolyn Barrett, the latest researcher to win a prestigious Sir Charles Hercus Health Research Fellowship, awarded by the Health Research Council of New Zealand.

Dr Barrett, who is based in the Department of Physiology at the University of Auckland, hopes to understand the link between the unconscious bodily functions

linked to the central nervous system, commonly known as the ‘fight or flight’ response, and the development of high blood pressure. This would mean that clinicians will have a better idea of which patients are likely to be at risk.

Dr Barrett believes that renal sympathetic nerve activity, commonly caused by stress, may be a precursor to an increase in blood pressure.

“You typically hear about people who are stressed and a stressed person tends to have an increase in sympathetic nerve activity, causing a constriction of the blood vessels, so that may be one mechanism of how a stressful job could cause an increase in blood pressure.”

“We know that in humans there is an increase in sympathetic nerve activity in people with a family background of hypertension, and also in borderline hypertensive people,” she says.

“But there doesn’t seem to be such convincing evidence that there’s an increase in sympathetic nerve activity in people who have long-term, established hypertension. That tends to suggest that the increase in sympathetic activity is involved in the development of hypertension in the first place and there’s pretty good evidence that it’s specifically activity to the kidney that produces increases in hypertension.”

Dr Barrett’s Hercus Fellowship project will be in two parts - the first further investigating what’s specific about renal sympathetic nerve activity. The second part of the project will involve trying to translate that to people and see how a change in renal sympathetic activity can be measured in them, says Dr Barrett.

“We know that we can’t directly measure renal sympathetic activity in humans but there are a number of measures that we can use, such as recording muscle sympathetic activity.”

Being able to reliably predict renal sympathetic nerve activity may provide them with a marker that is more accurate and less flawed, and much better for use in the clinical setting.

Established to build New Zealand’s future capability in world-class research, the Sir Charles Hercus Health Research Fellowship, valued at $0.5M over four years, is designed to support outstanding post-doctoral scientists establish careers as independent health researchers. The scheme has proved an effective incentive and mechanism for retaining some of our most promising talent in New Zealand.

The Sir Charles Hercus Health Research Fellowship was named in recognition of the contributions that Sir Charles Hercus (1888-1971) made to biomedical, clinical, and public health research during a distinguished 36-year career at the University of Otago, and his dedicated service to the Medical Research Council.

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