Abstract 14252: Cumulative Apolipoprotein B Blood Concentrations During Early Adulthood and Incident Atherosclerotic Cardiovascular Disease Risk After Age 40 Years: The Coronary Artery Risk Development in Young Adults Study

Abstract

Introduction: The associations between cumulative exposure to apolipoprotein B (apoB) containing lipoproteins across early adult life and incident ASCVD in later life have not been quantified. Methods: Of 4945 eligible Coronary Artery Risk Development in Young Adults (CARDIA) cohort participants we used NMR to measure apoB in 3110 participants who had samples available from the years 2, 7, 15, and 30 exams. To mitigate biases from missingness of data we conducted multiple imputation for apoB levels for the residual 1,835 participants without NMR measures of apoB. We estimated the participant-specific apoB throughout the exposure period (ages 19 to 40y) using nonparametric spline models. The area under the apoB/age curve was calculated as cumulative exposure and expressed in mg/dL*years. To quantify the association between cumulative apoB exposure during early life with incident ASCVD after age 40y we used demographic- and risk factor-adjusted* Cox regression models (see table). We used a restricted cubic spline to examine the pattern of association across the range of cumulative apoB exposure. Results: 4945 CARDIA participants were followed for a total of 88664 person*years; 255 incident ASCVD events occurred after age 40y. Participants with higher cumulative apoB levels were more likely to be men; and have higher BMI, BP, glucose, and tobacco use. In demographic and risk factor adjusted models a 100mg/dL*yr difference in cumulative apoB from ages 19 to 40y (representing a mean yearly difference of about +5mg/dL) was associated with HR 1.15 (95% CI:1.10-1.19) and HR 1.10 (95%CI:1.06-1.15) for ASCVD events, respectively. At apoB exposures >1700mg/dL*y (>80mg/dL/y) there was a strong, direct association with incident ASCVD after age 40y. Conclusion: Prevention strategies that reduce apoB exposures in early adult life will likely attenuate ASCVD risks later in life; targeting a usual apoB level < 80mg/dL may provide maximal benefit.