1. Department of Preventive Medicine, Yonsei University College of Medicine, Seoul, Korea.
2. Cardiovascular and Metabolic Diseases Etiology Research Center, Yonsei University College of Medicine, Seoul, Korea.
3. Division of Health and Nutrition Survey, Centers for Disease Control and Prevention, Cheongju, Korea.
4. Department of Epidemiology, Harvard T.H. Chan School of Public Health, Boston, MA, USA.