1. Division of Diabetes, University of Texas Health Science Center at San Antonio, San Antonio, TX
2. Diabetes and Obesity Clinical Research Center, Department of Medicine, Hamad General Hospital, Doha, Qatar
3. Department of Clinical and Experimental Medicine, University of Pisa School of Medicine, Pisa, Italy
4. Division of Cardiology, University of Texas Health Science Center at San Antonio and South Texas Veterans Health Care System, San Antonio, TX