Higher visit-to-visit systolic blood pressure variability early in life may predict CVD and all-cause mortality in middle age, according to research published in JAMA Cardiology on Jan. 22.
The study, which drew on data from the large-scale CARDIA (Coronary Artery Risk Development in Young Adults) registry, sought to analyze BP patterns over the life course, Yuichiro Yano, MD, PhD, and colleagues wrote in the journal. Current American College of Cardiology/American Heart Association BP guidelines and recommendations from the U.S. Preventive Services Task Force state physicians should consider blood pressure as a composite of readings over time, but the authors said little is known about the clinical relevance of variability.
“Prior studies have demonstrated that higher visit-to-visit BP variability and greater rate of change in BP over time are each associated with an increased risk for cardiovascular disease events, independently of mean BP levels,” Yano et al. wrote, noting those studies were also conducted in adults aged 50 or up. “Furthermore, little is known regarding specific BP patterns spanning from young adulthood to midlife that may be associated with CVD events in later life, independently of a single BP measurement in midlife.”
The team’s cohort study included 3,394 black and white patients who were enrolled in the CARDIA study between 1985 and 1986. Systolic BP patterns were measured at baseline and at two, five, seven and 10 years into follow-up, and visit-to-visit BP variability was estimated as BP variability independent of the mean (VIM).
By the tenth year of the study, patients were on average 35 years old and 45.9% were black, 55.7% were women and 3% were taking antihypertensive medication. Over the next two decades, 162 CVD events and 181 deaths occurred in the population.
Yano and colleagues reported that at the year 10 mark, the hazard ratios for CVD events for each 1-standard-deviation-increase in systolic BP measures were 1.25 for mean SBP, 1.23 for VIM SBP and 0.99 for annual change of SBP. The only BP pattern associated with all-cause death was VIM SBP, which was linked to a 24% increased likelihood of all-cause mortality.
Because BP variability was the only factor associated with all-cause mortality in the study, Yano et al. wrote that it can’t be determined whether high visit-to-visit BP variability is a causal driver for CVD events or a simply marker of poor health. Other studies should also look at BP variability in a more clinical context, since for their work BP was obtained in a highly controlled research environment that may not reflect everyday practice.
“The present study extends existing knowledge by demonstrating the association of long-term visit-to-visit BP variability among young adults without known CVD with CVD events and all-cause mortality in later life, and the associations were present among individuals not taking antihypertensive medication,” the authors wrote. “These findings suggest that the assessment of visit-to-visit BP variability may help identify young adults at increased risk for cardiovascular disease and all-cause mortality.”