title: HDL anti-oxidant function associates with LDL level in young adults.
abstract: OBJECTIVE
  The primary objective was to evaluate predictors of HDL anti-oxidant function in young adults.
  
  
  BACKGROUND
  High-density lipoprotein (HDL) cholesterol is considered a protective factor for cardiovascular disease (CVD). However, increased levels are not always associated with decreased cardiovascular risk. A better understanding of the importance of HDL functionality and how it affects CVD risk is needed.
  
  
  METHODS
  Fifty non-Hispanic white subjects from the Testing Responses on Youth (TROY) study were randomly selected to investigate whether differences in HDL anti-oxidant function are associated with traditional cardiovascular risk factors, including carotid intima media thickness (CIMT), arterial stiffness and other inflammatory/metabolic parameters. HDL anti-oxidant capacity was evaluated by assessing its ability to inhibit low-density lipoprotein (LDL) cholesterol oxidation by air using a DCF-based fluorescent assay and expressed as a HDL oxidant index (HOI). The associations between HOI and other variables were assessed using both linear and logistic regression.
  
  
  RESULTS
  Eleven subjects (25%) had an HOI ≥ 1, indicating a pro-oxidant HDL. Age, LDL, high sensitivity C-reactive protein (hsCRP), and paraoxonase activity (PON1), but not HDL, were all associated with HOI level in univariate linear regression models. In multivariate models that mutually adjusted for these variables, LDL remained the strongest predictor of HOI (0.13 increase in HOI per 1 SD increase in LDL, 95% CI 0.04, 0.22). Atherogenic index of plasma, pulse pressure, homocysteine, glucose, insulin, CIMT and measurements of arterial stiffness were not associated with HOI in this population.
  
  
  CONCLUSIONS
  These results suggest LDL, hsCRP and DBP might predict HDL anti-oxidant function at an early age.
authors.affiliation: Department of Preventive Medicine, USC Keck School of Medicine, 2001 N. Soto Street, Los Angeles, CA 90089, United States. Electronic address: breton@usc.edu.
authors.forename: Carrie V
authors.initials: CV
authors.lastname: Breton
authors.affiliation: Division of Cardiology, Department of Medicine, David Geffen School of Medicine, University of California, Los Angeles, CA 90095, United States.
authors.forename: Fen
authors.initials: F
authors.lastname: Yin
authors.affiliation: Department of Preventive Medicine, USC Keck School of Medicine, 2001 N. Soto Street, Los Angeles, CA 90089, United States.
authors.forename: Xinhui
authors.initials: X
authors.lastname: Wang
authors.affiliation: Department of Preventive Medicine, USC Keck School of Medicine, 2001 N. Soto Street, Los Angeles, CA 90089, United States.
authors.forename: Ed
authors.initials: E
authors.lastname: Avol
authors.affiliation: Department of Preventive Medicine, USC Keck School of Medicine, 2001 N. Soto Street, Los Angeles, CA 90089, United States.
authors.forename: Frank D
authors.initials: FD
authors.lastname: Gilliland
authors.affiliation: Division of Cardiology, Department of Medicine, David Geffen School of Medicine, University of California, Los Angeles, CA 90095, United States.
authors.forename: Jesus A
authors.initials: JA
authors.lastname: Araujo
mesh_terms: D000293:Adolescent; D000328:Adult; D000975:Antioxidants / Q000737:chemistry*; D043303:Aryldialkylphosphatase / Q000097:blood*; D002097:C-Reactive Protein / Q000378:metabolism; D002318:Cardiovascular Diseases / Q000097:blood*; D059168:Carotid Intima-Media Thickness; D008076:Cholesterol, HDL / Q000097:blood*; D008078:Cholesterol, LDL / Q000097:blood*; D005260:Female; D064368:Healthy Volunteers; D006801:Humans; D007249:Inflammation / Q000097:blood; D008297:Male; D010100:Oxygen / Q000737:chemistry; D012044:Regression Analysis; D012307:Risk Factors; D059289:Vascular Stiffness; D055815:Young Adult
chemical_list: D000975:Antioxidants; D008076:Cholesterol, HDL; D008078:Cholesterol, LDL; D002097:C-Reactive Protein; D043303:Aryldialkylphosphatase; C468406:PON1 protein, human; D010100:Oxygen
keywords: Antioxidant; Atherosclerosis; High density lipoprotein; Paraoxonase