Hypertriglyceridemia and especially increased levels of apoCIII in TGRL (TGRL-CIII) in normotriglyceridemic subjects are now recognized as risk factors for the atherosclerotic lesion progression. On the other hand, the efflux of cholesterol from peripheral cells, the first step of reverse cholesterol transport (RCT) has been shown to be protective against atherosclerosis. In a previously reported study, normolipidemic men with and without coronary artery disease (CAD), were compared. Subjects with CAD had a two-fold higher levels of TGRL-CIII (p0.001) than subjects without CAD. Moreover, the magnitude or duration of postprandial TG response to a test meal (60 per cent fat) was 30 per cent greater (p0.05) in the former than in the latter subjects. This clearance delay was significantly correlated with fasting TGRL-CIII levels (p0.001). ApoCIII distribution between TGRL and HDL in fasting state and specifically the levels of TGRL-CIII reflect and may predict the extent of postprondial TG clearance. To explore the first step of RCT, the fasting plasma capacity to promote cholesterol efflux from FU5AH cells was determined in two other groups of normolipidemic subjects with (n