Susceptibility of small, dense, low-density lipoproteins to oxidative modification in subjects with the atherogenic lipoprotein phenotype, pattern B.
Level 4 - case-series / case-control
Cross-sectional comparative laboratory study using human plasma samples
PubMed 8475928 · doi:10.1016/0002-9343(93)90144-e
What was done
The study compared the susceptibility of low-density lipoprotein (LDL) to copper sulfate-induced oxidative modification between individuals with lipoprotein phenotype pattern B (small, dense LDL; 5 men, 2 women) and pattern A (larger, more buoyant LDL; 7 men, 3 women). Six LDL density subfractions were isolated from plasma. Plasma lipids, lipoproteins, apolipoprotein B, mean LDL particle diameter, oxidation lag time, and oxidation rates were measured.
What was found
Oxidation lag time was inversely related to LDL density across both groups (p < 0.001) with no independent effect of overall phenotype. The LDL subfraction containing the major peak demonstrated a significantly shorter lag time in pattern B than in pattern A subjects (p < 0.05). In addition, pattern B subjects had a significantly higher rate of oxidation in subfraction 1, containing triglyceride-rich lipoprotein remnants (p < 0.005). The abstract reports p-values but no raw numerical means or effect sizes.
Why it matters
This study provides an ex vivo mechanistic basis for the higher atherogenic risk seen in pattern B individuals, linking smaller, denser LDL particles and triglyceride-rich remnants to increased oxidative susceptibility.
Limits
The sample size was very small (n = 17 total: 10 pattern A, 7 pattern B). Susceptibility to oxidation was evaluated using ex vivo copper-induced oxidation rather than in vivo physiological measures, and absolute values for oxidation kinetics were omitted from the abstract.
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.