Background. Experimental studies in animals suggest that
apolipoprotein (
apo) C-I is an important regulator of
triglycerides in fasting and postprandial conditions and associated with
carotid atherosclerosis. Methods. A cross-sectional study was conducted with 81 subjects, aged 56-80 years recruited from a population health survey. The participants underwent a fat tolerance test (1 g fat per Kg
body weight) and
carotid atherosclerosis was determined by ultrasound examination. VLDL particles, Sf 20-400, were isolated and their
lipid composition and
apoC-I content determined. Results. The carotid plaque area increased linearly with the number of
apoC-I molecules per VLDL particles (P = 0.048) under fasting conditions. Fasting
triglycerides increased across tertiles of
apoC-I per VLDL particle in analyses adjusted for
apoC-II and -C-III,
apoE genotype and traditional cardiovascular risk factors (P = 0.011). The relation between
apoC-I in VLDL and serum
triglycerides was conveyed by
triglyceride enrichment of VLDL particles (P for trend <0.001. The amount of
apoC-I molecules per VLDL was correlated with the total (r = 0.41, P < 0.0001) and incremental (r = 0.35, P < 0.001) area under the postprandial
triglyceride curve. Conclusions. Our findings support the concept that the content of
apoC-I per VLDL particle is an important regulator of
triglyceride metabolism in the fasting and postprandial state and associated with carotid athrosclerosis.