Results from a recently published study suggest blood pressure begins to decline up to 18 years before death, with the sharpest dip occurring in the final two years.

Researchers used primary care and hospitalization records from the United Kingdom to identify 46,634 people who had at least six blood pressure measurements over a 20-year span and who died at age 60 or older. The study cohort was 51.7 percent female, and the average age at death was 82.4 years.

Systolic and diastolic blood pressures (SBP and DBP) peaked 14 to 18 years before death, respectively, and then progressively decreased with sharper drops close to death, reported Joao Delgado, PhD, and colleagues in JAMA Internal Medicine. Mean SBP reductions ranged from 8.5 millimeters of mercury in individuals dying in their 60s to 22 mm Hg in people dying at age 90 or older. Decreases in DBP were proportionally similar but smaller in number.

“Overall, 64 percent of patients experienced SBP decreases of greater than 10 mm Hg,” Delgado et al. wrote. “Decreases in SBP were present without antihypertensive treatment but were steepest in patients with treated hypertension, dementia, heart failure and late-life weight loss. To our knowledge, this analysis provides the first evidence that SBP and DBP decrease for 14 or more years before death.”

Both SBP and DBP tend to increase as people progress from childhood to middle age. But previous studies reported conflicting results about what happens to blood pressure in the progression from middle age to old age and from old age to death, according to the researchers.

In addition to providing prognostic value of declining blood pressure in elderly patients, the new results could inform improved design of clinical trials, Delgado and colleagues wrote. Failing to account for this factor could bias results of trials with blood pressure measurements.

The authors suggested future studies focus on the “specific mechanisms” involved in late-life blood pressure decreases, which may inform clinical care decisions for those patients.

In a related editorial, James S. Goodwin, MD, with the Sealy Center on Aging at the University of Texas Medical Branch, said this study is a reminder of the difference between being one year older and one year closer to death.

“One straightforward interpretation of these findings is that many people who die in old age have been on a dying trajectory for a decade or more,” he wrote. “Something is happening to them that is not happening in people of the same age who are not going to die over the next decade.”

The predictive value of Delgado et al.’s study is most important, wrote Goodwin, who reported feeling regret when he was unable to project survival time for one of his patients with inoperable stomach cancer. Perhaps this study—and others highlighting end-of-life trajectories—will help both physicians and patients know what to expect, Goodwin said.

“The challenge for physicians treating the very elderly is when to ‘let go,’ when to stop urging more social engagement, more exercise, more food, and to realize that our patients are near death,” Goodwin wrote. “No physician wants to clutter the last 10 to 20 months of a person’s life with irrelevant concerns and activities. Surely an individual in the last year of life has more important things to think about.”