Subject screening will be performed by the Penn State Clinical Translational Research Center (CTRC) medical staff and will include a physical exam by a clinician, anthropometry, and a chemical and lipid profile, liver and renal function. Participants meet with a registered dietitian to determine their caloric energy requirements and identify food preferences. The interview includes surveying the subject's physical activity over the previous 7 days.
Subjects will undergo baseline microdialysis experiments to examine the function of the blood vessels in the skin microcirculation. Subjects will also go through a baseline assessment of conduit vessel endothelial and vascular smooth muscle function with brachial artery flow-mediated vasodilation (FMD), and sublingual nitroglycerin. Following baseline experiments, subjects participate in 4 controlled feeding periods, each 8 days in duration. The controlled feeding periods are assigned in a randomized order. At the end of each 8-day controlled dietary period, subjects will repeat microdialysis experiments, brachial artery FMD, and responsiveness to sublingual nitroglycerin.
