High-fat Meal Impairs Vascular Compliance in a Subgroup of Young Healthy Subjects

Postprandial hypertriglyceridemia impairs endothelial function and may possibly worsen vascular compliance by increasing oxidative stress. Large (C1) and small (C2) artery compliance, glucose, insulin, and triglycerides (TGs) were measured hourly for 6 hours in 18 young healthy volunteers after a low-fat meal and a high-fat meal, with and without antioxidant vitamins. C1 and C2 declined significantly for 6 hours after fat ingestion in 8 subjects ("fat reactors") and increased in 10 ("nonreactors"). Fat reactors had higher fasting and peak serum TGs after fat loading and increased baseline glucose and insulin levels and homeostasis model assessment of insulin resistance (HOMA(IR)). Fasting insulin correlated with C1 and C2 only in fat reactors. After fat intake, plasma nitric oxide metabolites decreased more in fat reactors than in nonreactors (17.0% +/- 5.1% vs 4.8% +/- 2.1%; P < .05). In fat reactors, pretreatment with antioxidant vitamins before the high-fat meal blunted the fall in C1 but not in C2. Compliance was unchanged after the low-fat meal. Normal weight young subjects with an insulin resistance phenotype show significantly decreased vascular compliance, increased postprandial TG peaks, and markedly reduced plasma nitric oxide metabolites after a high-fat meal.