1. Department of Preventive Medicine, College of Medicine; Graduate School; Korea University, Seoul, Republic of Korea.
2. National Health Institute Service, Health Insurance Policy Research Institute, Wonju, Republic of Korea.
3. Department of Public Health, Graduate School; Korea University, Seoul, Republic of Korea.
4. Division of Endocrinology and Metabolism, Department of Internal Medicine, Myongji Hospital, Hanyang University College of Medicine, Goyang, Republic of Korea.