1. Department of Diabetes, Soleiyu Asahi Clinic , Maebashi Gunma 371-0014 , Japan
2. Department of Orthopedic Surgery, Tone Chuo Hospital , Numata Gunma 378-0012 , Japan
3. Department of Medicine, Division of Endocrinology, Albert Einstein College of Medicine , Bronx, NY 10461 , USA
4. Department of Medicine and Molecular Science, Gunma University Graduate School of Medicine , Maebashi Gunma 371-8511 , Japan