Assessing blood pressure over time may help adults understand their risk of stroke and death

A population-based study found that adults whose blood pressure increased rapidly had a high risk of stroke and death. The researchers said that tracking a person’s blood pressure over time may be beneficial in assessing their risk for stroke and mortality.

Lead researcher M. Arfan Ikram, MD, PhD, of Erasmus MC University Medical Center in Rotterdam, Netherlands, and colleagues published their results online in Hypertension on May 9.

“Blood pressure should be measured regularly because it can change markedly over the course of a couple years, and put you at high risk for an adverse event," Ikram said in a news release. “Since the risk of stroke and death differ across these trajectory paths, they are potentially important for preventive strategies.”

For this analysis, the researchers examined 6,745 participants from the Rotterdam Study, which enrolled patients who were at least 55 years old and were living in Ommoord, a suburb of Rotterdam. They measured blood pressure twice in the right arm during each of five follow-up visits from 1990 to 2011.

They defined stroke as “a syndrome of rapidly developing clinical signs of focal (or global) disturbance of cerebral function, with symptoms lasting 24 hours or longer or leading to death and no apparent cause other than of vascular origin.”

After a mean follow-up period of 13.5 years, 1,053 strokes had occurred.

The researchers identified four trajectories of systolic blood pressure in the participants and used joint latent class mixed modeling to model their risk of stroke and competing causes of death.

The class 1 group included 4,938 participants whose systolic blood pressure increased gradually from an average of 120 mm Hg at 55 years old to 160 mm Hg at 95 years old. The class 2 group included 822 participants whose systolic blood pressure increased from 120 mm Hg at age 55 to 200 mm Hg at age 95. The 870 participants in the class 3 group had moderate mid-life blood pressure (an average of 140 mm Hg) that remained relatively consistent over time, while the 115 participants in the class 4 group had high mid-life blood pressure (an average of 160 mm Hg) that decreased after age 65.

The researchers found that the class 2 and class 4 groups had the highest risk of stroke and death from non-stroke diseases by age 80. The class 3 group had a similar risk of death compared with the class 1 group, although the class 3 group had the highest risk of stroke.

“Assessing trajectories of blood pressure provides a more nuanced understanding of the associations between blood pressure, stroke, and mortality,” the researchers wrote. “In particular, high blood pressure and rapidly increasing blood pressure patterns are associated with a high risk of stroke and death, while moderately high blood pressure is only related to an increased risk of stroke. Future studies should explore the potential etiologic significance of these patterns.”

The researchers also cited a few limitations of the study, including that they could not examine the associations among stroke subtypes. They also only obtained a maximum of five blood pressure measurements per person. They also did not have information on blood pressure before the participants turned 55 years old.

“Future studies should examine the lifetime trajectory of blood pressure and the risk of stroke,” the researchers wrote.