1. Department of Internal Medicine, Hallym University Sacred Heart Hospital, Hallym University College of Medicine, Anyang, Korea.
2. Department of Statistics and Actuarial Science, Soongsil University, Seoul, Korea.
3. Department of Internal Medicine, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
4. Asan Diabetes Center, Asan Medical Center, Seoul, Korea.