1. Division of Endocrinology and Metabolism, Department of Medicine, Faculty of Medicine, Khon Kaen University , Khon Kaen 40002 , Thailand
2. Division of Metabolism, Endocrinology, and Diabetes, Department of Internal Medicine, University of Michigan , Ann Arbor, MI 48109 , USA
3. Department of Pharmacology, University of Michigan , Ann Arbor, MI 48109 , USA
4. Endocrinology & Metabolism Section, Medicine Service, LTC Charles S. Kettles VA Medical Center , Ann Arbor, MI 48104 , USA