Significant Increase of Apolipoprotein B48 Levels by a Standard Test Meal in Type 2 Diabetic Patients with Nephropathy

Abstract

We investigated postprandial changes of apolipoprotein (apo) B48 in type 2 diabetics at different stages of diabetic nephropathy in order to explore non-traditional lipid abnormalities in diabetic nephropathy. Twenty-two healthy controls and 56 type 2 diabetics with normoalbuminuria (NA), microalbuminuria (MA), and overt albuminuria (OA) were enrolled. Blood samples were taken at 0, 1, 2, 4, 6 h after the ingestion of Test meal A (460 Kcal, 18 g fat). The maximal increase of triglyceride (TG) was 40% above baseline in controls and 17% above baseline in diabetics. The incremental area under the curve (iAUC) of TG, however, was comparable among controls and diabetics with NA, MA, and OA. The maximal increase of apoB48 was 92% above baseline in controls and 56-88% above baseline in diabetics. Apo B48-iAUC was significantly higher in diabetics than in controls, and diabetics with OA exhibited the highest apoB48-iAUC among the diabetic subgroups. Small dense low-density lipoprotein-cholesterol (LDL-C) was elevated in diabetic nephropathy, and apoB48-iAUC was positively associated with the level of sd-LDL-C. ApoB48 is a sensitive marker for postprandial lipemia, a condition which is significantly increased in diabetic nephropathy and associated with an increase of potent atherogenic sd- LDL particles.