Postprandial hyperglycemia on vascular endothelial function: mechanisms and consequences

Vascular endothelial dysfunction precedes atherosclerosis and contributes to cardiovascular disease (CVD), which accounts for one-third of all deaths in the United States. Chronic hyperglycemia, such as that associated with diabetes, is well known to impair vascular function. However, recent evidence demonstrates that acute or postprandial hyperglycemia (PPH) not only exacerbates vascular endothelial dysfunction in individuals with chronic hyperglycemia but also transiently impairs vascular function in healthy individuals. Postprandial hyperglycemia has been shown to better predict future CVD mortality compared with fasting glucose in both diabetic and normoglycemic individuals. Compelling evidence exists suggesting that PPH-mediated insults to the vascular endothelium contribute to CVD, especially in pathophysiologic conditions whereby vascular recovery is compromised. Although the mechanisms by which PPH induces vascular dysfunction is not fully understood, oxidative stress-mediated disruptions in nitric oxide homeostasis are implicated as key events leading to vascular dysfunction associated with PPH. This review aims to highlight the findings of clinical studies using functional indices of vascular function to demonstrate that PPH impairs vascular function. We will also discuss the evidence showing the central involvement of oxidative stress in dysregulating nitric oxide homeostasis and contributing to PPH-mediated vascular endothelial dysfunction. Lastly, this review will identify areas of knowledge that remain limited and will provide recommendations for future investigation to more fully define PPH as an important risk factor for CVD.