1. Division of Endocrinology, Diabetes, and Metabolism, University of Pennsylvania Health System, Philadelphia, Pennsylvania.
2. Philadelphia Veterans Affairs Medical Center, Philadelphia, Pennsylvania.
3. Institute for Translational Medicine and Therapeutics, University of Pennsylvania Health System, Philadelphia, Pennsylvania.
4. Center for Clinical Epidemiology and Biostatistics, University of Pennsylvania Health System, Philadelphia, Pennsylvania.
5. Division of General Internal Medicine, University of Pennsylvania Health System, Philadelphia, Pennsylvania.
6. Beltsville Human Nutrition Research Center, U.S. Department of Agriculture, Beltsville, Maryland.
7. Department of Clinical Studies, Section of Biostatistics, University of Pennsylvania School of Veterinary Medicine, New Bolton Center, Kennett Square, Pennsylvania.