Postprandial retinyl palmitate and squalene metabolism is age dependent

Most of our awake time is spent in a postprandial state. It has not been investigated in detail whether the post-prandial clearance of triglyceride-rich lipoproteins is age dependent. In addition, postabsorptive squalene metabolism has not been studied in relation to age. Accordingly, we investigated postprandial lipid metabolism in six young (22-25 years of age) and eight old (78-79 years of age) healthy men by use of an oral fat load containing 345,000 IU of vitamin A and 0.5 g of squalene as postprandial markers. Postprandial samples were drawn after 3, 4, 6, 9, 12 and 24 hours after the fat load. The retinyl palmitate area under the incremental curve of the old subjects was higher in plasma than that of the young subjects (p < .01). The pattern of postprandial very low density lipoprotein squalene responses differed significantly in the old compared with the young subjects (p < .01), but the areas under the incremental curve did not differ. Postprandial retinyl palmitate and squalene concentrations correlated significantly at 3-12 hours (p < .01). These data suggest that postprandial lipoprotein metabolism measured by retinyl palmitate and squalene is retarded with increasing age.