Abstract MP15: Total and HDL Cholesterol Trajectories in Early Adulthood and Coronary Artery Calcification in Middle Age: The CARDIA Study
Background: High total (TC) and low HDL cholesterol are independent risk factors for the development of CHD; however, their long-term trajectories and its association with subclinical measures of atherosclerosis remain unknown. We aimed to identify cholesterol (Chol) trajectories 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. Cholesterol was measured at baseline and yrs 2, 5, 7, 10, 15, 20, and 25. At each exam participants’ cholwas categorized into the following risk strata: (1) untreated TC <200 and favorable HDL; (2) untreated TC <200 and low HDL; (3) untreated TC 200-239 and favorable HDL; (4) untreated TC 200-239 and low HDL; (5) TC ≥ 240 or on lipid-lowering medication. Low HDL was defined as < 35 in men and <45 in women. Group-based modeling (PROC TRAJ) was used to identify trajectories in chol strata (coded as 1-5 and analyzed as a continuous variable) over time, optimal number of trajectories determined comparing BIC. Logistic regression was used to examine the association between trajectories and CAC> 0 at yr 25 adjusted for age, sex, race, blood pressure, smoking, diabetes and BMI.
Results: We identified 6 distinct trajectories in TC and HDL levels (fig): trajectories 1 - 6 included 28.2%, 15.8%, 32.4%, 11.2%, 7.5% and 4.9% of the population respectively. As compared to individuals who maintained ideal chol levels (group 1) those in trajectories 2-6 were more likely to have CAC> 0. Results were similar for CAC >100 and after adjustment for chol level at year 25 and/or at baseline, suggesting that trajectories in chol levels are independent predictors of CAC in middle age.
Discussion: Current CVD risk estimation techniques take into account single measurements of cholesterol. However, these findings suggest that understanding long-term trajectories in cholesterol may offer additional insight into an individual’s likelihood of having CAC which may better inform long-term CVD risk estimation.
- © 2013 by American Heart Association, Inc.