1. Department of Metabolic Medicine, Osaka University Graduate School of Medicine, Osaka 565-0871, Japan
2. Department of Diabetes Care Medicine, Osaka University Graduate School of Medicine, Osaka 565-0871, Japan
3. Department of Metabolism and Atherosclerosis, Osaka University Graduate School of Medicine, Osaka 565-0871, Japan
4. Department of Pathology, Tohoku University Graduate School of Medicine, Sendai 980-8574, Japan