1. Health Administration Center, Niigata University , Niigata, Japan
2. Division of Clinical Nephrology and Rheumatology, Niigata University Graduate School of Medical and Dental Sciences , Niigata, Japan
3. Department of Rheumatology, Niigata Rheumatic Center , Niigata, Japan
4. Division of Orthopedic Surgery, Niigata University Graduate School of Medical and Dental Sciences , Niigata, Japan
5. Department of Nephrology and Hypertension, Fukushima Medical University , Fukushima, Japan
6. Division of Orthopedic Surgery, Tsubame Rosai Hospital , Niigata, Japan