1. Department of Cardiology, Gachon University Gil Medical Center, Incheon, Korea.
2. Gachon Cardiovascular Research Institute, Incheon, Korea.
3. Cardiovascular Medicine, Hokko Memorial Clinic, Health Sciences University of Hokkaido, Sapporo, Japan.
4. Cardiovascular Medicine, Juntendo University Graduate School of Medicine, Tokyo, Japan.
5. Department of Geriatrics, Nagoya University Graduate School of Medicine, Nagoya, Japan.
6. Department of Medicine, Division of Endocrinology, Diabetes and Nutrition, University of Maryland School of Medicine, Baltimore, USA.