1. Division of Endocrinology, Diabetes, and Metabolism, University of Colorado Anschutz Medical Campus , Aurora, CO, USA 80045
2. Department of Veterans Affairs, Rocky Mountain Regional Veterans Medical Center , Aurora, CO, USA 80045
3. Division of GI, Trauma and Endocrine Surgery, University of Colorado Anschutz Medical Campus , Aurora, CO, USA 80045
4. Department of Pathology, University of Colorado School of Medicine , Aurora, CO, USA 80045