1. Department of Nutrition and Dietetics, Severance Hospital, Yonsei University Health System, Seoul 120-752, Korea.
2. Department of Anesthesiology and Pain Medicine, Anesthesia and Pain Research Institute, Yonsei University College of Medicine, Seoul 120-752, Korea.
3. Department of Internal Medicine, Yonsei University College of Medicine, 134 Shinchon-dong, Seodaemun-gu, Seoul 120-752, Korea.