1. Department of Preventive Medicine; School of Medicine; Kyung Hee University; Seoul Korea
2. Institute of Clinical Research; School of Medicine; Inha University; Incheon Korea
3. Department of Family Medicine; Kangbuk Samsung Hospital; School of Medicine; Sungkyunkwan University; Seoul Korea
4. Department of Internal Medicine; Kangbuk Samsung Hospital; Sungkyunkwan University; Seoul Korea
5. Total Healthcare Center; Kangbuk Samsung Hospital; School of Medicine; Sungkyunkwan University; Seoul Korea