Abstract 18927: HDL Efflux Capacity Correlates with Mean HDL Size and HDL Particle Number: The Chicago Healthy Aging Study
Introduction: Though it is known that the capacity of high-density lipoproteins (HDL) to participate in reverse cholesterol transport varies among individuals, the extent to which efflux capacity depends on HDL particle number and size is not well established.
Methods: Cholesterol efflux capacity and NMR spectroscopy were performed on serum from 402 Chicago Healthy Aging Study participants (ppts). The cholesterol efflux assay was performed using radiolabeled cholesterol, J774 macrophages, and samples depleted of ApoB-containing lipoproteins as previously published. NMR spectroscopy was used to characterize lipoprotein particle number and size. Spearman rho was used to assess correlation between normalized efflux and NMR-derived lipoprotein particle number and size measures.
Results: Ppts had a mean age of 73 y, 66% were male; mean fasting glucose was 100 mg/dl, mean BMI was 24.2 kg/m2, mean blood pressure was 125/74 mmHg, and 57% were using lipid lowering medications. Normalized HDL efflux capacity correlated with both mean HDL particle size (Spearman rho=0.50 p<0.0001) and HDL particle number (Spearman rho=0.38 p<0.0001) as assessed by NMR spectroscopy (See Figure). The strongest correlation was seen with large HDL particle number (Spearman rho=0.56, p<0.0001), while a weaker but still positive correlation was seen with medium-sized HDL particle number (Spearman rho=0.20, p<0.0001). An inverse correlation was observed between normalized efflux capacity and small HDL particle number (Spearman rho=-0.14, p=0.005).
Conclusions: These data lend support to the hypothesis that differences in HDL efflux capacity are in part mediated by differences in HDL particle size and number. Whereas larger HDL subtypes are associated with enhanced efflux capacity, smaller HDL is not.
Author Disclosures: R.K. Mutharasan: None. J.T. Wilkins: None. A.T. Singh: None. J.D. Berry: None. M.L. Daviglus: None. D.M. Lloyd-Jones: None. C.S. Thaxton: None.
- © 2014 by American Heart Association, Inc.