Blood pressure in the elderly begins to gradually decrease about 14 years before death, according to a new study published today in JAMA Internal Medicine .
Researchers from UConn Health and the University of Exeter Medical School in the United Kingdom observed 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 that the decrease in blood pressure was more pronounced in patients with dementia, heart failure, late weight loss, and those who had high blood pressure to begin with. But the long-term decreases also occurred without the presence of any of these diagnoses.
"Our work highlights the importance of conducting research to evaluate older patients like those seen in medical practices everywhere," said George Kuchel, one of the study's authors. director of the Center for Aging at the University of Connecticut at UConn Health.
However, Kuchel emphasized, "I would be very concerned if someone interpreted our article suggesting that hypertension should not be treated later in life or that they should stop doing it, their blood pressure medications."
The findings should make both doctors and researchers carefully consider what low blood pressure means for older patients, he added.
Doctors have known for some time that in the average person, blood pressure increases from childhood to middle age. But normal blood pressure in the elderly has been less certain.
Some studies have indicated that blood pressure may decrease in older patients and it has been hypothesized that the treatment of hypertension explains the lower blood pressures during late life. But this study found that the decrease in blood pressure was also present in those without hypertension diagnosis or antihypertensive medications.
In addition, the evidence was clear that the declines were not simply due to the early deaths of people with high blood pressure.  More research is needed to find out why blood pressure decreases in the elderly in this way. "Observational studies like ours must be followed by rigorous clinical trials in order to guide clinical care guidelines," Kuchel said.
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João Delgado et al, Trajectories of blood pressure in the 20 years prior to death, JAMA Internal Medicine (2017). DOI: 10.1001 / jamainternmed.2017.7023