Adipocyte-Derived Extracellular Vesicles, Weight Loss, and Endothelial Function

Inclusion criteria: * Age ≥40 years * BMI \<25 kg/m2 and BMI \>25 kg/m2 for Phase 1 and BMI \>25 kg/m2 for Phase 2. Rationale for defining obesity as BMI \>25 kg/m2 Exclusion criteria: * Current smoker * Chronic overt medical condition (e.g., evidence of coronary artery disease on resting ECG, any history of myocardial infarction or stroke, or cancer, diabetes based on fasting blood glucose concentration) * Alcohol abuse or dependence defined as more than 14 standard drinks/week and no more than 4 standard drinks/day for men and 7 standard drinks/week and 3 standard drinks/day for women (a standard drink is defined as 12 ounces of beer, 5 ounces of wines, 1 ½ ounces of 80-proof distilled spirits) reported during the medical history/physical exam * Stage III hypertension (systolic blood pressure \>160 mmHg and/or diastolic blood pressure \>100 mmHg) * Regular vigorous aerobic/endurance exercise (\>3 bouts/week, \>30 minutes/bout at a workload \>6 METS) * Women who are pregnant or breastfeeding * History of anaphylaxis to betadine, lidocaine, iodine * Raynaud's disease * History of clotting disorders * Anyone taking blood thinners and clotting medications * Anyone taking statin medication * Planned pregnancy in coming 4-6 months