title: Discordance Between Apolipoprotein B and LDL-Cholesterol in Young Adults Predicts Coronary Artery Calcification: The CARDIA Study.
abstract: BACKGROUND
  High levels of apolipoprotein B (apoB) have been shown to predict atherosclerotic cardiovascular disease (CVD) in adults even in the context of low levels of low-density lipoprotein cholesterol (LDL-C) or non-high-density lipoprotein cholesterol (non-HDL-C).
  
  
  OBJECTIVE
  This study aimed to quantify the associations between apoB and the discordance between apoB and LDL-C or non-HDL-C in young adults and measured coronary artery calcium (CAC) in midlife.
  
  
  METHODS
  Data were derived from a multicenter cohort study of young adults recruited at ages 18 to 30 years. All participants with complete baseline CVD risk factor data, including apoB and year 25 (Y25) CAC score, were entered into this study. Presence of CAC was defined as having a positive, nonzero Agatston score as determined by computed tomography. Baseline apoB values were divided into tertiles of 4 mutually exclusive concordant/discordant groups, based on median apoB and LDL-C or non-HDL-C.
  
  
  RESULTS
  Analysis included 2,794 participants (mean age: 25 ± 3.6 years; body mass index: 24.5 ± 5 kg/m(2); and 44.4% male). Mean lipid values were as follows: total cholesterol: 177.3 ± 33.1 mg/dl; LDL-C: 109.9 ± 31.1 mg/dl; non-HDL-C: 124.0 ± 33.5 mg/dl; HDL-C: 53 ± 12.8 mg/dl; and apoB: 90.7 ± 24 mg/dl; median triglycerides were 61 mg/dl. Compared with the lowest apoB tertile, higher odds of developing Y25 CAC were seen in the middle (odds ratio [OR]: 1.53) and high (OR: 2.28) tertiles based on traditional risk factor-adjusted models. High apoB and low LDL-C or non-HDL-C discordance was also associated with Y25 CAC in adjusted models (OR: 1.55 and OR: 1.45, respectively).
  
  
  CONCLUSIONS
  These data suggest a dose-response association between apoB in young adults and the presence of midlife CAC independent of baseline traditional CVD risk factors.
authors.affiliation: Department of Preventive Medicine, Northwestern University Feinberg School of Medicine, Chicago, Illinois. Electronic address: jwilkins@nm.org.
authors.forename: John T
authors.initials: JT
authors.lastname: Wilkins
authors.affiliation: Department of Preventive Medicine, Northwestern University Feinberg School of Medicine, Chicago, Illinois.
authors.forename: Ron C
authors.initials: RC
authors.lastname: Li
authors.affiliation: Department of Medicine (Cardiology), McGill University, Montreal, Quebec, Canada.
authors.forename: Allan
authors.initials: A
authors.lastname: Sniderman
authors.affiliation: Department of Preventive Medicine, Northwestern University Feinberg School of Medicine, Chicago, Illinois.
authors.forename: Cheeling
authors.initials: C
authors.lastname: Chan
authors.affiliation: Department of Preventive Medicine, Northwestern University Feinberg School of Medicine, Chicago, Illinois.
authors.forename: Donald M
authors.initials: DM
authors.lastname: Lloyd-Jones
mesh_terms: D000328:Adult; D001055:Apolipoproteins B / Q000097:blood*; D015415:Biomarkers / Q000097:blood; D015992:Body Mass Index; D008076:Cholesterol, HDL / Q000097:blood*; D008078:Cholesterol, LDL / Q000097:blood*; D003331:Coronary Vessels / Q000473:pathology*; D005260:Female; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D016017:Odds Ratio; D011237:Predictive Value of Tests; D015203:Reproducibility of Results; D012307:Risk Factors; D014481:United States / Q000453:epidemiology; D061205:Vascular Calcification / Q000097:blood / Q000175:diagnosis / Q000453:epidemiology
chemical_list: D001055:Apolipoproteins B; D015415:Biomarkers; D008076:Cholesterol, HDL; D008078:Cholesterol, LDL
keywords: early adult life course; lipid; risk factor