Small dense LDL and VLDL predict common carotid artery IMT and elicit an inflammatory response in peripheral blood mononuclear and endothelial cells.
Level 4 - case-series / case-control
Cross-sectional analysis of cohort participants combined with in vitro cell assays
PubMed 19376517 · doi:10.1016/j.atherosclerosis.2009.03.017
What was done
Lipoprotein cholesterol subfractions and LDL buoyancy (LDL-relative flotation rate, LDL-RF) were evaluated in 156 healthy subjects randomly selected from the PLIC (Progressione Lesione Intimale Carotidea) study. The authors analyzed correlations between lipoprotein subclasses, cardiometabolic risk factors, and common carotid artery intima-media thickness (IMT). They also compared pro-inflammatory mRNA expression in isolated peripheral blood mononuclear cells (PBMC) and cultured endothelial cells exposed to lipoprotein subfractions from subjects with large LDL (pattern A) versus small dense LDL (pattern B).
What was found
The abstract reports no exact numerical values, correlation coefficients, or regression parameters. LDL-RF correlated positively and significantly with weight, body mass index, waist, hip, waist/hip ratio, triglycerides, fasting glycemia, and common carotid IMT, and inversely with HDL-C. Multivariate analysis showed IMT was independently associated with age, LDL-RF, and HDL-C; only triglyceride-rich lipoproteins (TGRL) and small dense LDL (sdLDL) subclasses independently predicted IMT variance. PBMCs from pattern B subjects showed increased mRNA expression of pro-inflammatory molecules compared to pattern A. In endothelial cells, pattern B TGRL strongly induced pro-inflammatory genes compared to pattern A TGRL, whereas sdLDL from either pattern was less effective with comparable effects between patterns.
Why it matters
This paper links atherogenic lipoprotein subfractions (sdLDL and TGRL) to subclinical vascular remodeling (carotid IMT) in a healthy population and shows that these particles trigger distinct inflammatory responses in circulating immune and endothelial cells.
Limits
The clinical component is a cross-sectional analysis in a modest sample (n=156), which prevents causal or temporal inferences. The abstract omits all numerical effect sizes, confidence intervals, and exact p-values. In vitro cellular assays may not fully reflect in vivo atherogenesis or hard clinical endpoints.
Cited by
- supports Large pattern A LDL particles are less prone to oxidative stress, inflammation, and plaque rupture compared to small, dense pattern B LDL particles.