 Arm 1: 1. Able to fast overnight or for 6 hours 2. Non-diabetic 3. Age 40 years 4. Negative pregnancy test, postmenopausal, or surgically sterilized 5. Negative mammogram at Mayo Clinic within the last 15 months defined as screening mammogram or subsequent diagnostic workup with BI-RADS 1 or 2 final assessment 6.No current breast concerns 