Substitution of glucose with whole eggs or egg whites during an oral glucose challenge mitigates impairments in postprandial vascular endothelial function by attenuating hyperglycemia‐mediated increases in lipid peroxidation

Abstract

Postprandial hyperglycemia (PPH) is a better predictor of CVD than fasting glucose, with evidence supporting that PPH transiently impairs vascular endothelial function (VEF) in an oxidative stress‐dependent manner. We hypothesized that co‐ingesting egg‐based meals with a glucose challenge would mitigate PPH‐mediated impairments in VEF by limiting lipid peroxidation. In a randomized, cross‐over study, prediabetic obese adults (n = 20; 31.9 ± 1.6 y; 105.0 ± 0.9 mg/dL; 31.1 ± 0.7 kg/m2) ingested isocaloric test meals (400 kcal) containing 100 g glucose (GLUCOSE), or 75 g glucose with 1.5 whole eggs (EGG), 7 egg whites (EGG‐W), or 2 egg yolks (EGG‐Y) prior to evaluating brachial artery flow‐mediated dilation (FMD, %) and plasma glucose and malondialdehyde (MDA) at 30 min intervals for 3 h. Change in FMD (ΔFMD%) during GLUCOSE was maximally lowered at 30 min, and improved at 60 min relative to 30 min, and was restored to levels no different from baseline at 90–180 min. This was accompanied by increases in plasma glucose that peaked at 30 min, and remained elevated through 120 min, until returning to concentrations not different from baseline at 150 min. MDA was higher at 30–120 min relative to baseline, and by 120 min it was significantly lower than peak (60 min) concentrations and not different from baseline concentrations. Regardless of egg‐based meal, ΔFMD% was lower at 30 min relative to baseline, but only ΔFMD% of EGG‐Y was reduced to the extent observed in GLUCOSE. At 60 min, ΔFMD% of EGG and EGG‐W were restored to levels not different from baseline, whereas GLUCOSE and EGG‐Y remained lower than baseline levels, and not different from ΔFMD% at 30 min. By 90 min, ΔFMD% of all treatments were not different from each other and were restored to levels not different from baseline with the exception that EGG‐Y remained lower through 180 min. Relative to GLUCOSE, ΔFMD% AUC0–3 h was increased to a similar extent in EGG and EGG‐W whereas EGG‐Y was not different from GLUCOSE and was lower than those of EGG and EGG‐W. Plasma glucose AUC0–3 h and ΔMDA AUC0–3 h were not different between GLUCOSE and EGG‐Y, but were similarly lower in EGG and EGG‐W compared with GLUCOSE and EGG‐Y. Collectively, replacing a portion of carbohydrate during a glucose challenge with whole eggs or egg whites, but not egg yolks, mitigates PPH‐mediated impairments in VEF by limiting glycemia and lipid peroxidation. Supported by the Egg Nutrition Center.Support or Funding InformationEgg Nutrition Center