According to a recent investigation, high blood pressure in people aged over 85 may be associated with reduced mortality. The researchers also found that the risk of mortality was even lower for older adults with moderate or severe frailty.
In 2017, a number of health organizations, including the American Heart Association (AHA) and American College of Cardiology, lowered their definitions of high blood pressure.
Previously, the thresholds were 140/90 millimeters of mercury (mm Hg) for people younger than 65 and 150/80 mm Hg for those aged 65 and older.
But are these tighter guidelines truly helpful for older adults, particularly for adults with frailty?
As the authors of the new study point out, most data relating to hypertension and older adults do not necessarily represent frail older adults.
This is because an insufficient number of these adults have participated in randomized clinical trials, due to comorbidities, limited life expectancy, problems with cognition, and factors relating to medication.
For these reasons, predicting cardiovascular or all-cause mortality from blood pressure among older adults is still challenging and uncertain.
To help address this issue, Jane Masoli — a National Institute for Health Research doctoral fellow and specialist registrar in geriatric medicine at the University of Exeter, in the United Kingdom — and colleagues carried out a new study.
Masoli and the team set out to examine associations between mortality and blood pressure in the health records of 415,980 older adults.
They recently published their results in the journal Age and Ageing.
The researchers applied statistical tools, such as Cox proportional-hazards models, to test the association over a follow-up period of at least 10 years.
They stratified their analysis by frailty level, using an electronic frailty index that includes classifications of fit (nonfrail) and mild, moderate, and severe frailty.
The analysis found that the risk of cardiovascular problems such as heart attacks increased when systolic blood pressure was over 150 mm Hg.
However, systolic blood pressure above 130–139 mm Hg was linked with lower mortality risk, “particularly in moderate to severe frailty or above 85 years.”
Specifically, when comparing systolic blood pressure of 150–159 mm Hg (hypertension) with that in the range of 130–139 mm Hg, the researchers found that hypertension was associated with a 6% reduction in mortality risk among nonfrail older adults.
Among older people with hypertension and moderate to severe frailty, the team observed a 16% reduction in mortality risk during the study period.
“Hypertension was not associated with increased mortality at ages above 85 or at ages 75–84 with moderate/severe frailty, perhaps due to complexities of coexisting morbidities,” write the authors.
They conclude, “The priority given to aggressive [blood pressure] reduction in frail older people requires further evaluation.”
“Internationally,” says Masoli, the study’s lead author, “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 personalized blood pressure management in older adults.”
– Jane Masoli
She cautions, however, “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.”