BLOOD PRESSURE VARIABILITY AND HISTORY OF CARDIOVASCULAR EVENTS IN MAY MEASUREMENT MONTH 2019 PARTICIPANTS

Abstract

Objective: Increased blood pressure variability (BPV) is associated with negative health outcomes, but its determinants, and how best to measure it, remain unclear. We aimed to explore differences in four commonly used measures of BPV by clinical factors in the May Measurement Month (MMM) 2019 global survey. Design and method: We performed an observational analysis of BP readings from MMM 2019 survey participants. Volunteer adult (18 years or older) participants were surveyed via convenience sampling from 92 countries in May 2019. Each participant had three seated BP readings. Four indices of diastolic and systolic BPV were calculated for participants with all three BP readings: the standard deviation (SD), coefficient of variation (CV), absolute difference between the second and first BP readings (AR), and the variation independent of the mean (VIM). Factors examined included use of antihypertensive medication, being obese (body mass index greater than 29 kg/m2), and having a diagnosis of diabetes, myocardial infarction, or stroke. For each BPV index and factor, a regression model was created with the index as the outcome. Each model was adjusted for mean BP (based on the average of the second and third BP readings), age, sex, an interaction between age and sex, and antihypertensive medication use. Age and mean BP were each included as natural cubic splines with five knots. Results: Data from for 1,133,008 (75.1%) participants were included. The mean age was 45.6 (SD 16.6) and 52.0% were female. Coefficient estimates were similar for SD, VIM, and CV (Figure 1). Lower systolic and diastolic BPV were seen in participants who reported use of antihypertensive medication, and in those with a previous history of stroke, diabetes, or MI. There were small but statistically significant differences by obesity status. Conclusions: Diabetes, a history of myocardial infarction or stroke and the use of antihypertensive medication were associated with lower within-visit BPV, independent of age or sex. This may reflect underlying physiological differences between groups or differences in BPV-lowering effects resulting from different lifestyle choices or medication usage of these participants.