High-glucose mixed nutrient meal ingestion impairs skeletal muscle microvascular blood flow in healthy young males.

BACKGROUND AND AIMS: Oral glucose ingestion leads to impaired muscle microvascular blood flow (MBF) which likely contributes to acute hyperglycemia-induced insulin resistance. We investigated whether incorporating lipids and protein into a high-glucose load could prevent postprandial MBF dysfunction. METHODS: Ten healthy young males (age: mean 27 years old, 95% lower and upper confidence interval [24, 30]; height: 180 cm [174, 185]; weight: 77 kg [70, 84]) ingested a high-glucose (1.1 g/kg glucose) mixed nutrient meal (10 kcal.kg(-1); 45% carbohydrate, 20% protein, and 35% fat) in the morning after an overnight fast. Femoral arterial blood flow was measured via Doppler ultrasound and thigh MBF was measured via contrast enhanced ultrasound prior to meal ingestion, and 1 hour and 2 hours postprandial. Blood glucose and plasma insulin were measured at baseline and every 15 minutes throughout the 2 hour postprandial period. RESULTS: Compared to baseline, thigh muscle microvascular blood volume, velocity and flow were significantly impaired at 60 minutes postprandial (-25%, -27%, -46%, respectively; all p < 0.05) and to a greater extent at 120 minutes postprandial (-37%, -46%, -64%; all p < 0.01). Heart rate and femoral arterial diameter, blood velocity and flow, were significantly increased at 60 minutes and 120 minutes postprandial (all p < 0.05). Higher blood glucose area under the curve was correlated with greater MBF dysfunction (R(2) = 0.742; p < 0.001). CONCLUSION: Ingestion of a high-glucose meal, despite the inclusion of lipids and protein, impairs MBF in healthy individuals for up to 2 hours postprandial.