Blood pressure in the elderly gradually begins to decrease about 14 or so years before death, according to a new large-scale study published today in the Journal of the American Medical Association Internal Medicine.

Researchers from the University of Exeter Medical School and UConn Health in the US looked at the electronic medical records of 46,634 British citizens who had died at age 60 or older. The large sample size included people who were healthy as well as those who had conditions such as heart disease or dementia.

They found blood pressure declines were steepest in patients with dementia, heart failure, late-in-life weight loss, and those who had high blood pressure to begin with. But long-term declines also occurred without the presence of any of these diagnoses.

Professor David Melzer, from the University of Exeter Medical School, said: “Our large-scale study has shown for the first time that blood pressure drops for around 14 years before death, in older patients. We now need more research to understand why this happens. It is important for physicians to understand as much as possible around aging and blood pressure, to help personalize treatment.”

Professor Melzer also has a visiting Professorship at the University of Connecticut Center on Aging.

"Our work highlights the importance of conducting research evaluating older patients like those seen in physician practices everywhere," said Professor George Kuchel, one of the study authors and director of the University of Connecticut Center on Aging at UConn Health.

However, Professor Kuchel emphasized, "I would be very concerned if anyone were to interpret our article as suggesting that hypertension should not be treated in late life or that they should stop their blood pressure medications."

The findings should make both doctors and researchers carefully consider what dropping blood pressure really means for older patients, he added.

Doctors have long known that in the average person, blood pressure rises from childhood to middle age. But normal blood pressure in the elderly has been less certain.

Some studies have indicated that blood pressure might drop in older patients, and treatment for hypertension has been hypothesized as explaining late-life lower blood pressures. But, this study found blood pressure declines were also present in those without hypertension diagnoses or anti-hypertension medication prescriptions.

Further, the evidence was clear that the declines were not due simply to the early deaths of people with high blood pressure.

More research is needed to figure out why blood pressure declines in the elderly in this way. "Observational studies such as ours need to be followed by rigorous clinical trials in order to guide clinical care guidelines," said Professor Kuchel.

Other study authors included Scott Welsh, fellow in UConn Health's Geriatrics Program; David Melzer and colleagues from the University of Exeter; and Luigi Ferrucci, director of the National Institute on Aging Intramural Program.