Comprehensive assessment of postischemic vascular reactivity in Hispanic children and adults with and without diabetes mellitus

Background: To examine the whole postischemic hyperemic response period in Hispanic children and adults with and without type 2 diabetes mellitus (T2DM) and offer insight into the potential adaptive mechanisms involved in the arterial response to disturbances in vascular homeostasis. Methods: Ninety-eight adults and 124 children of Hispanics participated in the study. Endothelial function was assessed in the brachial artery using high-resolution ultrasonography (HRU). A continuous scan was taken for 5 min during the hyperemic response, flow velocity (FV) recordings and diameter measurements were obtained, and brachial arterial blood flow (BF) was calculated after the cuff deflation. Results: The increment in FV during the reactive hyperemic period was higher in obese and in diabetic children than in lean healthy children, although the time to reach peak brachial artery diameter (BAD) and the per cent increase in peak diameter were comparable in all three groups. In subjects with impaired glucose tolerance (IGT), the hyperemic peak increase in FV was comparable to those in healthy adults. In diabetic patients, the peak increase in BAD as well as the per cent increment in the diameter were reduced at 50-60 s after the release of the arm cuff. The time to reach the peak increase in diameter also was prolonged in diabetics when compared with healthy adults. Conclusion: Our study demonstrates clear differences in the normal vascular response between healthy children and healthy adults and discloses the presence of additional abnormalities in the flow-mediated vasodilation in diabetic and 'prediabetic' subjects.