[Small dense low density lipoprotein particles: mechanisms of formation, atherogenic properties, possibilities of modification of their content in blood plasma].

Atherogenic low density lipoproteins (LDL) consist of subfractions of particles with different dimensions, density, proportion of various lipid components, affinity to apo B/E receptors, susceptibility to oxidation, and other properties. As a rule spectrum of LDL particles has one predominant central peak and several (up to 6) additional peaks containing particles which are smaller or larger than particles of the main peak. There are also smaller and bigger particles within the main peak itself. In normolipidemia average diameter of particles of the predominant main peak exceeds 25.5 hm (profile A), in combined hyperlipidemia main peak consists of smaller (<25.5 hm) particles (profile B). It has been shown in many studies that because of several characteristics (lower affinity to apo B/E receptors, prolonged presence in blood stream, susceptibility to oxidation and uncontrolled entrapment by macrophages) small dense LDL particles play significant role in atherogenesis. The authors of this review have demonstrated that in subjects with abdominal obesity and concomitant metabolic risk factors in postprandial period after standard meal LDL spectrum shifts towards small particles and this shift persists during 6 hours after meal. An apparently atherogenic subfraction of large cholesterol ester loaded particles is also described in this paper.