1. Department of Internal Medicine, Division of Rheumatology, The University of Michigan, Ann Arbor, MI 48109, USA
2. STATinMED Research, Istanbul, Turkey
3. Social Security Institution, Ankara, Turkey
4. Central Bank of Turkey, Ankara, Turkey
5. Gastroenterology Clinic, Dıskapı Yıldırım Beyazıt Education and Research Hospital, Ankara, Turkey