1. Department of Internal Medicine, Pusan National University School of Medicine, Busan, Korea
2. Medical Research Institute, Pusan National University, Busan, Korea
3. Department of family medicine, Pusan National University School of Medicine, Busan, Korea
4. Department of Nuclear medicine, Pusan National University School of Medicine, Busan, Korea
5. Kim Yong Ki Internal Medicine Clinic, Busan, Korea