1. Department of Internal Medicine, School of Medicine, College of Medicine, National Cheng Kung University, Tainan 701, Taiwan
2. Tong-Yuan Diabetes Center, College of Medicine, National Cheng Kung University, Tainan 701, Taiwan
3. Institute of Clinical Medicine, College of Medicine, National Cheng Kung University, Tainan 701, Taiwan
4. Department of Internal Medicine, National Cheng Kung University Hospital, College of Medicine, National Cheng Kung University, Tainan 704, Taiwan
5. Department of Internal Medicine, Tainan Municipal Hospital (Managed by Show-Chwan Medical Care Corporation), Tainan 701, Taiwan