A study of U.S. veterans found higher systolic blood pressure variability was associated with increased risks of all-cause mortality, coronary heart disease, stroke and end-stage renal disease.
The researchers measured systolic blood pressure variability using the standard deviation of the systolic blood pressure values in each patient.
Lead researcher Elvira O. Gosmanova, MD, of Albany Medical College and Stratton Veterans Affairs Medical Center in Albany, New York, and colleagues published their results online in the Journal of the American College of Cardiology on Sept. 19.
The researchers mentioned that blood pressure fluctuates on a continuous basis and that the fluctuations typically remain consistent within patients. Recently, healthcare professionals have realized that visit-to-visit variability of blood pressure is the best measure of fluctuations.
For this study, the researchers identified more than 2.8 million patients who had eight or more outpatient blood pressure measurements in 2005 and 2006. The mean age of patients was 60 years old, while 94 percent were male and 78 percent were white.
Patients with higher systolic blood pressure variability were older, were more likely to be male, African American and unmarried, had lower income and higher prevalence of comorbid conditions and more frequently used all classes of antihypertensive medications.
During a median follow-up period of eight years, there were 484 deaths, which yielded a mortality rate of 22.87 per 1,000 person-years.
An adjusted model found that patients who were in the lowest quarter of systolic blood pressure variability had lower rates of all-cause mortality, coronary heart disease, stroke and end-stage renal disease compared with those with higher variability.
The researchers noted that higher systolic blood pressure variability remained predictive of worse survival and increased risk of incident coronary heart disease, stroke and end-stage renal disease in all subgroups.
They added that the study had a few limitations, including its observational design, which meant they could not make inferences about the causality of systolic blood pressure variability. They also mentioned that the study consisted of mostly male veterans, which limits the generalizability to other populations. In addition, they did not include information on smoking status and baseline proteinuria, which were potential confounders.
“Additional research is needed to understand the impact on clinical outcomes of interventions that reduce [systolic blood pressure variability],” the researchers wrote.