1. Department of Family Medicine, Korea University College of Medicine, Seoul, Korea
2. Division of Biostatistics, Graduate School of Public Health, Korea University College of Medicine, Seoul, Korea
3. Department of Preventive Medicine, Korea University College of Medicine, Seoul, Korea
4. Department of Rehabilitation Medicine, Korea University College of Medicine, Seoul, Korea
5. Department of Family Medicine, Eulji University School of Medicine, Seoul, Korea
6. Division of Endocrinology and Metabolism, Department of Internal Medicine, Korea University College of Medicine, Seoul, Korea