What is LDL particle size?

LDL (low-density lipoprotein) particle size refers to the size and density of LDL particles in the blood. These particles range in size from small and dense to large and buoyant. Importantly, smaller, denser LDL particles have a higher association with heart disease risk compared to larger, more buoyant particles.

This increased risk from smaller LDL particles is due to several factors:

1. Reduced receptor affinity: Smaller particles have less affinity for the LDL receptor, meaning they are not as readily removed from the bloodstream by the liver, causing them to circulate longer.
2. Increased artery interaction: Their prolonged circulation time means there is more opportunity for these smaller particles to interact with and adhere to artery walls.
3. Enhanced pro-inflammatory potential: The longer they circulate, the more they can undergo harmful transformations, such as oxidation, which promotes inflammation and contributes to the formation of plaques in arteries, a key event in atherosclerosis 1.

Understanding the size and density of LDL particles helps in refining risk assessment for cardiovascular diseases. The smaller and denser LDL particles, despite having less cholesterol per particle, are more atherogenic and potentially harmful 2.