1. Department of Rheumatology, Endocrinology and Nephrology; Faculty of Medicine and Graduate School of Medicine; Hokkaido University Graduate School of Medicine; Sapporo Japan
2. Department of Public Health; Hokkaido University Graduate School of Medicine; Sapporo Japan
3. The Hokkaido Centre for Family Medicine; Sapporo Japan
4. Department of Endocrinology and Metabolism; Graduate School of Medicine; Yokohama City University; Yokohama Japan