Abstract 048: Blood Pressure Trajectories in Early Adulthood and Coronary Artery Calcification in Middle Age: The CARDIA Study
Background: High blood pressure (BP) is an risk factor for the development of atherosclerosis; however, long-term trajectories in BP and their impact on CVD risk are poorly characterized. We aimed to identify trajectories in BP throughout early adulthood and to determine their association with presence of coronary artery calcification (CAC) during middle age.
Methods: We used data from the CARDIA study. BP was measured at baseline and years 2, 5, 7, 10, 15, 20, and 25. At each exam participants’ BP was categorized into the following risk strata: (1) untreated SBP <120 and DBP< 80; (2) untreated SBP 120-139 or DBP 80-89; (3) treated SBP <140 and DBP< 90; (4) SBP ≥ 140 or SBP ≥ 90. Group-based modeling (PROC TRAJ) was used to identify trajectories in BP strata (coded as 1-4 and analyzed as a continuous variable) over time. The optimal number of trajectories was determined comparing BIC. Logistic regression was used to examine associations between BP trajectory and CAC > 0 measured at yr 25, adjusted for age, gender, race, dyslipidemia, smoking, diabetes and BMI.
Results: We identified 5 distinct BP trajectories (fig): trajectories 1 thru 5 included 25.6%, 31.7%, 14.4%, 22.9% and 5.5% of the population, respectively. As compared to individuals who maintained ideal BP levels (group 1) trajectories with increasing BP levels had a greater odds of having CAC >0 (figure). Those who consistently had high levels (group 5) were 4 times more likely to have CAC >0 (OR 4.3, 95% CI 2.8-6.7) than those in trajectory 1. Results were similar for CAC >100. BP trajectory remained significant after adjustment for BP level at year 25 and/or at baseline, suggesting that trajectories in BP levels are independent predictors of CAC in middle age.
Discussion: Significant heterogeneity exists in the trajectories of blood pressure levels throughout young adulthood and these trajectories are associated with presence of subclinical atherosclerosis in middle age. Long-term trajectories in BP may assist in more accurate classification of an individual’s CVD risk.
- © 2013 by American Heart Association, Inc.