1. Division of Endocrinology and Metabolism, Department of Internal Medicine, College of Medicine; Korea University; Seoul; Korea
2. Department of Internal Medicine; Eulji University School of Medicine; Seoul; Korea
3. Diabetes Center; Eulji Hospital; Seoul; Korea
4. Department of Biostatistics, College of Medicine; Korea University; Seoul; Korea
5. Department of Pathology, College of Medicine; Korea University; Seoul; Korea