Abstract 14724: Heterogeneous Associations Between High Density Lipoprotein Composition and Visceral and Hepatic Fat by Ethnicity: Observations From the Dallas Heart Study
Background: It is well known that HDL composition, visceral adipose tissue, and hepatic fat, all markers of atherosclerotic risk, vary by ethnicity. However, it remains unknown whether the relationships between HDL composition and these adiposity phenotypes differ by ethnicity.
Methods: We analyzed data from the Dallas Heart Study, a probability-based sample of Dallas County adults, restricting analyses to participants free at study entry from malignancy, connective tissue disease, or HIV, and had the following measured: HDL-C concentration (HDL-C) and total particle number (HDL-P) by NMR; visceral adipose tissue (VAT) by MRI; and hepatic triglyceride content (HTGC) by 1.5-T 1H MR spectroscopy. Multivariable linear regression was performed to assess cross-sectional associations between HDL-C and HDL-P with VAT and log HTGC, stratified by ethnicity with statistical testing for interactions. Models were adjusted for traditional CV risk factors, BMI, log triglyceride, alcohol intake, lipid-modifying drugs, menopause status, hormone replacement therapy, and history of CV disease. Adjusted models included both HDL-C and HDL-P.
Results: The study comprised 2114 participants with median age 45, 46% women, 49% Black, and 17% Hispanic. HDL-C, HDL-P, VAT, and HTGC all differed significantly by ethnicity (Panel A). In multivariable analyses, HDL-C was inversely associated with VAT but not HTGC across all ethnicities, with stronger associations among Blacks (Pinteraction < 0.0001). HDL-P was positively associated with VAT and HTGC, but only among Blacks (Pinteraction < 0.0001; Panel B).
Conclusion: HDL-C and HDL-P have opposing and heterogeneous associations with visceral and hepatic adiposity phenotypes. These relationships differ by ethnicity with strongest associations among Blacks. These findings may provide insight into the relationship between ectopic fat deposition and atherosclerotic risk in this group.
- © 2013 by American Heart Association, Inc.