In non-diabetic subjects, the 75 g oral challenge induces a peak increase in systemic glucose at 1-hour post-administration at which time endothelial dysfunction is concomitantly detectable. Endothelial cells will be obtained via J-wire capture technique. A portion of the endothelial cells isolated from the J-wires will be used to measure mitochondrial network complexity prior hyperglycemic challenge, 1-hour post challenge, and 4 hours post challenge. The investigators will visualize the mitochondrial networks in these cells using our previously reported and validated immunofluorescence method using cytochrome c antibodies to tag the mitochondria. Network fragmentation (high number=greater fragmentation and fission) will be quantified by network fragmentation count calculated with ImageJ (NIH, Bethesda) using a validated protocol.