A largescale study led by the University of Exeter, published in Age and Ageing and funded by NIHR, analysed 415,980 electronic medical records of older adults in England.

The research was conducted after some countries have changed blood pressure guidelines to encourage clinicians to take measures to reduce blood pressure in a bid to improve health outcomes. UK blood pressure guidelines are within safe parameters for all. However, previous research has not considered the impact on frail older adults, who are often omitted from trials.

The team found that people aged 75 or over with low blood pressure (below 130/80 mmHg) had increased mortality rates in the follow-up, compared to those with normal blood pressure. This was especially pronounced in 'frail' individuals, who had 62% increased risk of death during the ten year follow-up.

Although high blood pressure increased risk of cardiovascular incidents, such as heart attacks, it was not linked to higher mortality in frail adults over 75. Older people aged 85 and over who had raised blood pressure actually had reduced mortality rates, compared to those with lower blood pressure, regardless of whether they were frail or not.

Jane Masoli, a geriatrician and NIHR Doctoral Research Fellow, who led the study as part of her PhD at the University of Exeter, said: "Internationally, guidelines are moving towards tight blood pressure targets, but our findings indicate that this may not be appropriate in frail older adults. We need more research to ascertain whether aggressive blood pressure control is safe in older adults, and then for which patient groups there may be benefit, so we can move towards more personalised blood pressure management in older adults."

She added: "We know that treating blood pressure helps to prevent strokes and heart attacks and we would not advise anyone to stop taking their medications unless guided by their doctor."