The status of fasting triglycerides as a risk factor for coronary artery disease (CAD) has been considered weak because in multivariate analyses, triglycerides tend to be eliminated by high density lipoprotein (HDL) cholesterol. To further evaluate the role of triglycerides in CAD, we employed postprandial lipemia as a more informative means of characterizing triglyceride metabolism. In 61 male subjects with severe CAD and 40 control subjects without CAD as verified by angiography, we measured cholesterol; triglycerides; HDL cholesterol; HDL 2 cholesterol; and apolipoproteins A-I, A-II, and B in fasting plasma and triglycerides before and 2, 4, 6, and 8 hours after a standardized test meal. Both the maximal triglyceride increase and the magnitude of postprandial lipemia (area under the triglyceride curve over 8 hours after the meal) were higher in cases than in control subjects. Single postprandial triglyceride levels 6 and 8 hours after the meal were highly discriminatory (p<0.001), and by logistic-regression analysis displayed an accuracy of 68% in predicting the presence or absence of CAD. In this respect, accuracy was higher than that of HDL 2 cholesterol (64%) and equal to that of apolipoprotein B (68%), the most discriminatory fasting parameter. Multivariate logistic-regression analysis was performed to reduce the number of risk factors to those that were statistically independent. This statistical procedure selected postprandial but not fasting triglycerides into the most accurate multivariate model, which also contained the accepted risk factors HDL 2 cholesterol, apolipoprotein B, and age. This model classified 82% of subjects correctly. We conclude that triglycerides are independent predictors of CAD in multivariate analyses including HDL cholesterol, provided that a challenge test of triglyceride metabolism such as postprandial lipemia is used. The study suggests that the metabolism of triglycerides is a critical determinant of cholesterol metabolic routing. The findings support the concept that the negative association between HDL cholesterol levels and CAD actually originates in part from a positive relation between CAD and plasma triglycerides, as ascertained in the postprandial state. (

In 16 members of two Austrian families affected by a missense mutation at codon 188 of the lipoprotein lipase (LPL) gene (8 heterozygous and 8 normal subjects), carrier status for the mutation as determined by DNA analysis was related to LPL activity in postheparin plasma, to the magnitude of postprandial lipemia, and to concentration, composition, and size of the major lipoprotein classes ofpostabsorptive plasma. Carriers exhibited clearly reduced LPL activity, normal fasting triglycerides, but pronounced postprandial lipemia. The carriers' impaired triglyceride tolerance, as evident in the postprandial state of challenge only, was associated with a fasting lipoprotein constellation characterized by

No abstract

In 11 patients with IIB hyperlipoproteinemia we studied fasting lipids, lipoproteins, lipoprotein-modifying enzymes, and postprandial lipid metabolism after a standardized oral fat load supplemented with vitamin A before and 12 weeks after treatment with fenofibrate, a third-generation fibric acid derivative. Fasting plasma cholesterol, triglycerides, low-density lipoprotein cholesterol decreased significantly (P < 0.05, P < 0.01, P < 0.01), high-density lipoprotein subfraction 3 cholesterol increased significantly (P < 0.05), and high-density lipoprotein subfraction 2 cholesterol remained unchanged. Postprandial lipemia, i.e., the integrated postprandial triglyceride concentrations corrected for the fasting triglyceride level, and postprandial chylomicron concentrations, as assessed by biosynthetic labeling of chylomicrons with retinyl palmitate, decreased by 40.6% and 60.1% (P < 0.05; P < 0.05), respectively. The activity of lipoprotein lipase (LPL) increased by 33.6% (P < 0.05); the increase in LPL during fenofibrate treatment was positively correlated with the increase in high-density lipoprotein cholesterol (r = 0.84; P < 0.005). Hepatic lipase and cholesteryl ester transfer protein mass and activity remained unchanged. We conclude that lipid-lowering therapy with fenofibrate ameliorates fasting and, more profoundly, postprandial lipoprotein transport in hypertriglyceridemia by curbing postprandial triglyceride and chylomicron accumulation, at least in part, through an increase in LPL activity.

Summary. We report the long-term metabolic observations made on 37 patients after simultaneous pancreas and kidney transplantation. Plasma C-peptide levels were above the physiological range in all patients and there was no significant difference between patients undergoing delayed duct occlusion (n=12) or those with drainage of exocrine secretion into the urinary bladder (n=25). HbA 1,, was equally at the upper end of the normal range in both subsets of patients. Mean fasting cholesterol (237 mg/dl) and triglycerides (122 mg/dl) were normal, and HDL-cholesterol was above normal with an average concentration of 77 mg/dl. Two patients underwent an oral fat tolerance test and showed extremely low postprandial lipaemia and very high lipoprotein lipase activities. We conclude that patients with a functioning pancreas graft persistently demonstrate normoglycaemia, elevated Cpeptide, and a very favourable lipid profile both in the fasting and the postprandial state.