Cumulative exposure to atherogenic lipoprotein particles in young adults and subsequent incident atherosclerotic cardiovascular disease

BACKGROUND AND AIMS: Atherogenic lipoprotein exposure during young adulthood increases the risk of atherosclerotic cardiovascular disease (ASCVD) later in life. The relationships between cumulative and usual yearly apolipoprotein B (apoB), low-density lipoprotein particle (LDL-P), and triglyceride-rich lipoprotein particle (TRL-P) exposure in early adult life and incident ASCVD was quantified. METHODS: Follow-up data of young adults aged 18 to <40 years from the longitudinal population-based Coronary Artery Risk Development in Young Adults (CARDIA) cohort were used. Cumulative early adult exposure of apoB, LDL-P, and TRL-P were defined over a 22-year exposure period (18 to <40 years). 'Usual' exposure to atherogenic lipid particles was calculated by dividing the cumulative exposure to apoB, LDL-P, and TRL-P by 22 years, and the hazard ratio was calculated between a 1 SD higher cumulative lipoprotein exposure with incident ASCVD after age 40 using adjusted Cox regression models. RESULTS: Among 4366 CARDIA participants, there were 241 ASCVD events after age 40 (mean follow-up of 19.3 years). A 1 SD higher cumulative exposure to apoB, LDL-P, and TRL-P was associated with unadjusted HRs of 1.53 [95% confidence interval (CI) 1.36-1.72], 1.54 (95% CI 1.36-1.75), and 1.48 (95% CI 1.30-1.68) for incident ASCVD after age 40, respectively. Adjustment for covariates yielded HRs for each measure of approximately 1.30. The hazard ratio for ASCVD increased after a usual apoB exposure of approximately 75 mg/dL/year from age 18 to <40. CONCLUSIONS: Cumulative exposure to atherogenic lipid particles in young adulthood increases the risk for incident ASCVD later in life. Apolipoprotein B concentration <75 mg/dL may represent a goal to maintain low risk in young adults.