Summary
Reverse cholesterol transport has become an important subject in scientific studies since 1975, when the high-density lipoprotein (HDL) hypothesis was introduced. The hypothesis stated that the reduction of plasma HDL concentration may in crease the development of atherosclerosis and ischaemic heart disease by disrupting cholesterol removal from the arterial wall. At that time, the lack of methodologies for determining HDL concentration lead to supporting the HDL hypothesis by research data based on high- density lipoprotein cholesterol (HDL-C) concentration measurements. This resulted in HDL-C concentration, in stead of HDL concentra tion, be com ing a biomarker for assessing the risk of atherosclerotic and cardiovascular disease. The data collected from scientific research during the last two decades resulted in rising doubts whether the HDL-C concentration is the most appropriate biomarker for assessing atherosclerotic and cardiovascular disease risk. The scientific research of HDL functions was set in motion in order to find out what had caused this phenomenon. Studies on HDL-mediated cholesterol efflux from peripheral tissues lead to a quantitative measurement of this process and to the naming of this quantitative measurement as the cholesterol efflux capacity. Further research on cholesterol efflux capacity allowed to make the assumption that it may be an independent atherosclerotic and cardiovascular disease biomarker that offers additional information on cholesterol homeostasis. Cholesterol efflux capacity measurement methods have more recently been in development; however, the standartization and result variability between methods still pose a challenge because of the different components used in these methods. Methodological improvements are very important in order to create a cholesterol efflux capacity measurement technique that could be routinely used in clinical laboratories, thus allowing bigger-scale population studies. These larger studies would allow assessing the real potential of the cholesterol efflux capacity in becoming an individual biomarker in the risk assessment of atherosclerotic and cardiovascular disease.
