1. Department of Internal Medicine, Daerim St. Mary's Hospital, Seoul, Korea.
2. Department of Biostatistics, Korea University College of Medicine, Seoul, Korea.
3. Department of Internal Medicine, Korea University College of Medicine, Seoul, Korea.
4. Department of Internal Medicine, Ajou University College of Medicine, Suwon, Korea.
5. Department of Internal Medicine, Inha University College of Medicine, Incheon, Korea.
6. Department of Internal Medicine, Hanyang University College of Medicine, Seoul, Korea.
7. Department of Internal Medicine, Kyung Hee University College of Medicine, Seoul, Korea.
8. Department of Food & Nutrition, Hoseo University, Asan, Korea.
9. Department of Medicine, Cheil General Hospital & Women's Healthcare Center, Kwandong University College of Medicine, Seoul, Korea.