Glycemic and insulinemic meal responses modulate postprandial hepatic and intestinal lipoprotein accumulation in obese, insulin

Background: Exacerbated postprandial lipemia is a risk factor for cardiovascular disease and is linked to insulin status. Limited data on the effect of dietary carbohydrate on postprandial lipoprotein accu- mulation are available. Objective: We tested the hypothesis that dietary carbohydrates with different glucose availability alter postprandial lipoprotein metabo- lism differently in obese, insulin-resistant subjects. Design: After an overnight fast, 9 subjects with central obesity and insulin resistance but normal triacylglycerolemia randomly ingested 2 test meals with comparable amounts of fat (28 -29 g) and digestible carbohydrate (91-94 g) but with different quantities of slowly avail- able glucose (SAG) in cereal products (17 or 2 g SAG/100 g for biscuits and wheat flakes, respectively). Blood samples were col- lected before and for 6 h after meal intakes. Results: The postmeal 0 -2-h areas under the curve (AUCs) for glycemia and insulinemia were significantly lower (P 0.05) after the biscuit meal than after the flakes meal. Plasma triacylglycerol concentrations increased significantly after the flakes meal but not after the biscuit meal (1.5-fold higher 0 - 6-h AUC for the flakes meal). Apolipoprotein B-100 concentrations in the triacylglycerol- rich lipoprotein fraction increased significantl y 2 h after the flakes meal but not after the biscuit meal (3-fold higher 0 - 6-h AUC for the flakes meal). Apolipoprotein B-48 concentrations increased (P 0.05) 4 h after the flakes meal but not after the biscuit meal (2.3-fold higher 0 - 6-h AUC for the flakes meal). Conclusion: Mixed meals containing slowly digestible carbohy- drate that induces low glycemic and insulinemic responses reduce the postprandial accumulation of both hepatically and intestinally derived triacylglycerol-rich lipoproteins in obese subjects with in- sulin resistance. Am J Clin Nutr 2004;80:896 -902.