Lipoprotein subfractions and carotid plaque: NMR analysis of triglyceride-rich vs LDL particle size concentrations (ELSA-Brasil study)

Abstract

Background: This study analyzed the cross-sectional association of elevated concentrations of low-density lipoprotein particles (LDLp) and triglyceride-rich lipoprotein particles (TRLp) with carotid artery plaque (CAP) in the ELSA-Brasil cohort.

Methods: Data from 3801 participants (median age: 50.0 years [IQR 44.0-57.0], 54.3% women) with no prior history of cardiovascular disease nor use of lipid-lowering medications were analyzed. CAP was assessed by ultrasonography, while nuclear magnetic resonance (NMR) spectroscopy was used to measure LDLp and TRLp concentrations according to size. Poisson regression models characterized the association of elevated lipid concentrations (≥1 SD above the mean) with CAP, adjusted for sociodemographic variables, cardiovascular risk factors, and for the concentration of high-density lipoprotein particles (HDLp), LDLp, and TRLp.

Results: The frequency of CAP was 33.9% (n = 1,287). Elevated concentrations of total TRLp (prevalence ratio [PR]:1.05 [95% CI:1.01-1.10]) and small-sized TRLp (PR:1.23 [95% CI:1.11-1.36]) were associated with CAP, but lost significance after adjustment for LDLp. Elevated LDLp concentration was associated with CAP in total (PR:1.10 [95% CI:1.05-1.15]) and in all the different sizes (large [PR:1.09], medium [PR:1.11] and small [PR:1.09]), regardless of TRLp. When both LDLp and TRLp were simultaneously included in a dedicated model, only LDLp remained associated with CAP (PR:1.11 [95% CI: 1.06-1.16]). By particle size, elevated small TRLp and elevated LDLp in all sizes were associated with CAP even when mutually adjusted.

Conclusion: The elevated concentration of small TRLp seems to portend an incremental residual likelihood of prevalent CAP beyond LDLp, whereas the association of LDLp with CAP remained consistent beyond classical risk factors and NMR-assessed HDLp and TRLp concentration.

Keywords: Atherosclerosis; Carotid artery plaque; Lipoprotein particles; Nuclear magnetic resonance spectroscopy; Triglyceride-rich lipoproteins; Ultrasonography.