1. Department of Gastroenterology and Hepatology, Okayama University Hospital, Okayama, Japan
2. Department of Endocrinology, Okayama City Hospital, Okayama, Japan
3. Department of Nephrology, Rheumatology, Endocrinology and Metabolism, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, Japan.